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1
Yu, Ze. "Liquid Redox Electrolytes for Dye-Sensitized Solar Cells." Doctoral thesis, KTH, Oorganisk kemi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-64139.
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This thesis focuses on liquid redox electrolytes in dye-sensitized solar cells (DSCs). A liquid redox electrolyte, as one of the key constituents in DSCs, typically consists of a redox mediator, additives and a solvent. This thesis work concerns all these three aspects of liquid electrolytes, aiming through fundamental insights to enhance the photovoltaic performances of liquid DSCs. Initial attention has been paid to the iodine concentration effects in ionic liquid (IL)-based electrolytes. It has been revealed that the higher iodine concentration required in IL-based electrolytes can be attributed to both triiodide mobility associated with the high viscosity of the IL, and chemical availability of triiodide. The concept of incompletely solvated ionic liquids (ISILs) has been introduced as a new type of electrolyte solvent for DSCs. It has been found that the photovoltaic performance of ISIL-based electrolytes can even rival that of organic solvent-based electrolytes. And most strikingly, ISIL-based electrolytes provide highly stable DSC devices under light-soaking conditions, as a result of the substantially lower vapor pressure of the ISIL system. A significant synergistic effect has been observed when both guanidinium thiocyanate and N-methylbenzimidazole are employed together in an IL-based electrolyte, exhibiting an optimal overall conversion efficiency. Tetrathiafulvalene (TTF) has been investigated as an organic iodine-free redox couple in electrolytes for DSCs. An unexpected worse performance has been observed for the TTF system, albeit it possesses a particularly attractive positive redox potential. An organic, iodine-free thiolate/disulfide system has also been adopted as a redox couple in electrolytes for organic DSCs. An impressive efficiency of 6.0% has successfully been achieved by using this thiolate/disulfide redox couple in combination with a poly (3, 4-ethylenedioxythiophene) (PEDOT) counter electrode material under full sunlight illumination (AM 1.5G, 100 mW/cm2). Such high efficiency can even rival that of its counterpart DSC using a state-of-the-art iodine-based electrolyte in the systems studied.The cation effects of lithium, sodium and guanidinium ions in liquid electrolytes for DSCs have been scrutinized. The selection of the type of cations has been found to exert quite different impacts on the conduction band edge (CB) of the TiO2 and also on the electron recombination kinetics, therefore resulting in different photovoltaic behavior.QC 20120124
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Wragg, David Alexander. "Electrolyte interactions in dye-sensitised solar cells : catalysis, corrosion and corrosion inhibition." Thesis, Swansea University, 2015. https://cronfa.swan.ac.uk/Record/cronfa43168.
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Khan, Md Imran. "A Study on the Optimization of Dye-Sensitized Solar Cells." Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4519.
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Considering biocompatibility, the Dye Sensitized Solar Cell (DSC) based on titanium dioxide should play a major role in the future of solar energy. In this ongoing study, different components and ambient process conditions for the fabrication of were investigated. Titanium dioxide substrate thickness and morphology was found to have a direct impact on the cell efficiency. Scanning Electron Microscopy (SEM) was used to investigate the TiO2 nanostructure. Different chemical treatments and electrolytes were also explored towards optimizing the cell performance. A group of porphyrin based organic dyes were synthesized and evaluated. Standard solar cell characterization techniques such as current-voltage and spectral response measurements were employed to evaluate the cell performance.
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Lai, Jessica Christine. "The use of nanostructured calcium silicate in solar cells : a thesis submitted to the Victoria University of Wellington in fulfilment of the requirements for the degree of Master of Science [in Chemistry] /." ResearchArchive@Victoria e-thesis, 2009. http://hdl.handle.net/10063/1053.
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Zhang, Jian. "INVESTIGATION OF THE EFFECTS OF LAYER THICKNESS ON DYE SENSITIZED SOLAR CELL PERFORMANCE." Miami University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=miami1377132624.
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Gao, Jiajia. "Electrolyte-Based Dynamics: Fundamental Studies for Stable Liquid Dye-Sensitized Solar Cells." Doctoral thesis, KTH, Tillämpad fysikalisk kemi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187025.
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The long-term outdoor durability of dye-sensitized solar cells (DSSCs) is still a challenging issue for the large-scale commercial application of this promising photovoltaic technique. In order to study the degradation mechanism of DSSCs, ageing tests under selected accelerating conditions were carried out. The electrolyte is a crucial component of the device. The interactions between the electrolyte and other device components were unraveled during the ageing test, and this is the focus of this thesis. The dynamics and the underlying effects of these interactions on the DSSC performance were studied. Co(bpy)32+/3+-mediated solar cells sensitized by triphenylamine-based organic dyes are systems of main interest. The changes with respect to the configuration of both labile Co(bpy)32+ and apparently inert Co(bpy)33+ redox complexes under different ageing conditions have been characterized, emphasizing the ligand exchange problem due to the addition of Lewis-base-type electrolyte additives and the unavoidable presence of oxygen. Both beneficial and adverse effects on the DSSC performance have been separately discussed in the short-term and long-term ageing tests. The stability of dye molecules adsorbed on the TiO2 surface and dissolved in the electrolyte has been studied by monitoring the spectral change of the dye, revealing the crucial effect of cation-based additives and the cation-dependent stability of the device photovoltage. The dye/TiO2 interfacial electron transfer kinetics were compared for the bithiophene-linked dyes before and after ageing in the presence of Lewis base additives; the observed change being related to the light-promoted and Lewis-base-assisted performance enhancement. The effect of electrolyte co-additives on passivating the counter electrode was also observed. The final chapter shows the effect of electrolyte composition on the electrolyte diffusion limitation from the perspectives of cation additive options, cation concentration and solvent additives respectively. Based on a comprehensive analysis, suggestions have been made regarding lithium-ion-free and polymer-in-salt strategies, and also regarding cobalt complex degradation and the crucial role of Lewis base additives. The fundamental studies contribute to the understanding of DSSC chemistry and provide a guideline towards achieving efficient and stable DSSCs.QC 20160517
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Casadio, Simone. "Development and optimization of fibre-shaped dye-sensitized solar cells employing an innovative fully organic sensitizer." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18608/.
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The quality of human life depends to a large degree on the availability of energy. In recent years, photovoltaic technology has been growing extraordinarily as a suitable source of energy, as a consequence of the increasing concern over the impact of fossil fuels on climate change. Developing affordable and highly efficiently photovoltaic technologies is the ultimate goal in this direction. Dye-sensitized solar cells (DSSCs) offer an efficient and easily implementing technology for future energy supply. Compared to conventional silicon solar cells, they provide comparable power conversion efficiency at low material and manufacturing costs. In addition, DSSCs are able to harvest low-intensity light in diffuse illumination conditions and then represent one of the most promising alternatives to the traditional photovoltaic technology, even more when trying to move towards flexible and transparent portable devices. Among these, considering the increasing demand of modern electronics for small, portable and wearable integrated optoelectronic devices, Fibre Dye-Sensitized Solar Cells (FDSSCs) have gained increasing interest as suitable energy provision systems for the development of the next-generation of smart products, namely “electronic textiles” or “e-textiles”. In this thesis, several key parameters towards the optimization of FDSSCs based on inexpensive and abundant TiO2 as photoanode and a new innovative fully organic sensitizer were studied. In particular, the effect of various FDSSCs components on the device properties pertaining to the cell architecture in terms of photoanode oxide layer thickness, electrolytic system, cell length and electrodes substrates were examined. The photovoltaic performances of the as obtained FDSSCs were fully characterized. Finally, the metal part of the devices (wire substrate) was substituted with substrates suitable for the textile industry as a fundamental step towards commercial exploitation.
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Cosar, Mustafa Burak. "The Development Of Bifacial Dye Sensitized Solar Cells Based On Binary Ionic Liquid Electrolyte." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615376/index.pdf.
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In this study, we investigated the effect of electrolyte composition, photoanode thickness, and the additions of GuSCN (guanidinium thiocyanate), NMB (N-methylbenimidazole), and SiO2 on the photovoltaic performance of DSSCs (dye sensitized solar cells). A bifacial DSSC is realized and irradiated from front and rear sides. The devices give maximum photovoltaic efficiencies for 70% PMII (1-propyl 3-ethylimidazoliumiodide)/30%(EMIB(CN)4)(1-ethyl-3-methyl-imidazolium tetracyano borate) electrolyte composition and 10 &mum thick photoanode coating which is considered to be the ideal coating thickness for the diffusion length of electrolyte and dye absorption. A significant increase in the photocurrent for DSSCs with optimum molarity of 0.1 M GuSCN was observed due to decreased recombination which is believed to be surface passivation effect at photoanode electrolyte interface suppressing recombination rate. Moreover, optimum NMB molarity was found to be 0.4 for maximum efficiency. Addition of SiO2 to the electrolyte both as an overlayer and dispersed particles enhanced rear side illuminated cells where dispersed particles are found to be more efficient for the front side illuminated cells due to additional electron transport properties. Best rear side illuminated cell efficiency was 3.2% compared to front side illuminated cell efficiency of 4.2% which is a promising result for future rear side dye sensitized solar cell applications where front side illumination is not possible like tandem structures and for cells working from both front and rear side illuminations.
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Bin, Kamarudin Muhammad Akmal. "Integration of liquid crystals with redox electrolytes in dye-sensitised solar cells." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/270351.
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This thesis examines the electro-optic, electric and electrochemical properties of liquid crystal (LC) materials in self-assembly systems, that is, liquid crystal-polymer electrolyte composites (LC-PEs), LC binary mixtures, and their potential application in dye-sensitised solar cells (DSSCs). The birefringence of LCs causes light modulation, which can be controlled by an applied voltage and electric field. In particular, the LCs are used as one of the components for the electrolyte redox couple which is responsible for charge transfer mechanism in DSSCs. In this work, LC-PEs were developed by dissolving LCs in polymer electrolytes; using a homologous series of cyanobiphenyls in a range of concentrations, alkyl chain lengths and dielectric permittivities. We found that doping the polymer electrolyte with 15% 4'-cyano-4'-pentylbiphenyl (5CB) improved ionic conductivity by up to 13 % compared to pure polymer electrolyte. Materials with positive dielectric permittivity and shorter alkyl chain length have been identified to be compatible with iodide/triiodide (I^-/I_3^-)-based polymer electrolytes. In DSSCs, 15% 5CB and 15% E7 LC-PEs exhibited the best efficiencies of 3.6 % and 4.0 %, respectively. In addition to LC-PEs, the self-assembly properties of smectic phase LCs were also utilised as templates for controlling the polymer structure in polymer electrolytes. A porous polymer network was prepared using various techniques including self-assembly, by applying an electric field and using a polyimide (PI) alignment layer. We found that the electrochemical and photovoltaic properties of these materials strongly correlated to the morphology/structure with the self-assembled structure, thus showing the best photovoltaic performance (5.9 %) even when compared with a reference solar cell (4.97 %). Finally, this thesis explores the interaction of LCs with graphene (Gr) in DSSC device architectures. Gr-based DSSCs were fabricated using different processing conditions, with the result being that Gr improved the performance of the DSSCs. The highest efficiency obtained was 5.48 % compared to the 4.86 % of a reference DSSC. The incorporation of LC-PEs in Gr-based DSSCs improved the performance of DSSCs was observed in devices with low concentrations of LCs due to the Gr inducing planar alignment of LCs. These results suggest a new strategy to improve DSSC efficiency by incorporating LC materials in the polymer electrolyte component. Even though these LCs are highly insulating, their self-assembly and dielectric polarisability help enhance ionic conductivity and optical scattering when doped into polymer electrolytes. This work can be extended in a fundamental way to elucidate the ionic conduction mechanism of LC-based electrolyte systems. Furthermore, it would be interesting if the benefits of using LC-PEs and smectic-templated polymer electrolytes (Sm-Pes) can be translated further in commercial electrochemical energy conversion systems.
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Yang, Wenxing. "Exploring Electronic Processes at the Mesoporous TiO2/Dye/Electrolyte Interface." Doctoral thesis, Uppsala universitet, Fysikalisk kemi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-310191.
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Dye sensitized solar cells (DSSCs) are an attractive way to convert light into electricity. Its development requires a detailed understanding and kinetic optimization of various electronic processes, especially those occurring at the mesoporous TiO2/dye/electrolyte interface. This dissertation work is focused on the exploration of the various electronic processes at the sensitized-electrode/electrolyte interface by using various electrochemical and photochemical methods. Firstly, an alternative redox couple—TEMPO/TEMPO·+ with a relatively high positive redox potential—is explored, aiming to reduce the energy loss during the dye regeneration process. Despite the fast dye regeneration, the charge recombination between the electrons in the conduction band of mesoporous TiO2 and the oxidized redox species is found to be the limiting factor of the device. Further, a more efficient tandem-electrolyte system is developed, leading to DSSCs with the power conversion efficiency of 10.5 % and 11.7 % at 1 sun and 0.5-sun illumination, respectively. An electron-transfer cascade process during dye regeneration by the redox mediators is discovered to be beneficial. Further stability studies on the device suggest the crucial role of TiO2/dye/electrolyte interfaces in the long-term stability of cobalt bipyridyl electrolyte-based DSSCs. On the fundamental level, the local electric field and Stark effects at the TiO2/dye/electrolyte interface are investigated in various aspects—including the charge compensation mechanism, the factors affecting the electric field strength, as well as its impact on charge transfer kinetics. These results give further insights about the TiO2/dye/electrolyte interface, and contribute to the further development and understanding of DSSCs.
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Benedetti, João Eduardo. "Preparação, caracterização e aplicação de eletrólitos polímericos gel em células solares TiO2/corante." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/248408.
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Orientador: Ana Flávia NogueiraTese (doutorado) - Universidade Estadual de Campinas, Instituto de Química
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Resumo: Este trabalho consistiu na preparação, caracterização e posterior aplicação de eletrólitos poliméricos gel em celulas solares de TiO2/corante. No Capítulo I, e apresentado uma introdução geral sobre células solares e eletrólitos poliméricos. O Capítulo II contém os objetivos deste trabalho. No Capítulo III, são preparados os eletrólitos polimérico gel utilizando a matriz polimérica de poli(oxido de etileno-co-2-(2-metoxietoxi) etil glicidil eter) (P(EO/EM)) contendo I2 e várias concentrações de g-butirolactona (GBL) e LiI. Esses eletrólitos foram caracterizados por medidas de calorimetria exploratória diferencial (DSC), ressonância magnética de Li (RMN), termogravimetria (TGA), difração de raios-X (DRX), condutividade e voltametria cíclica (VC). O eletrólito polimérico gel P(EO/EM)/GBL/LiI/I2 apresentou excelentes propriedades químicas e eletroquímicas. Esses eletrólitos foram aplicados nas células solares de TiO2/corante, conforme e apresentado no Capítulo IV. As células solares foram caracterizadas por meio das curvas de corrente-potencial (J-V), estimativa do tempo de vida do eletron e espectroscopia de absorção transiente (TAS). De modo geral, os dispositivos montados com o eletrólito polimérico (P(EO/EM)/GBL/LiI/I2 apresentaram um aumento da fotocorrente com a incorporação de GBL no eletrólito. Esse resultado e influência da maior difusão das especies redox no meio. Em contrapartida, o aumento da concentração de GBL no eletrólito também provocou uma acentuada perda no potencial de circuito aberto, o que foi relacionado ao aumento dos processos de recombinação na interfaces, contribuindo para a perda da eficiência das células solares. Para minimizar esses efeitos, no Capítulo V, e apresentada a caracterização por meio das curvas de corrente-potencial da célula solar de TiO2/corante montadas com o eletrólito P(EO/EM)/GBL/LiI/I2 preparado com terc-butilpiridina e éter coroa. A incorporação desses aditivos proporcionou um aumento de Voc das células solares e, consequentemente, da eficiência dos dispositivos. O Capítulo VI apresenta os testes de estabilidade das células solares de TiO2/corante preparadas com o eletrólito polimérico gel, no qual apresentou estabilidade apropriada durante 30 dias de teste. O Capítulo VII contém as principais conclusões deste trabalho e perspectiva de continuação para esta linha de pesquisa
Abstract: This thesis consisted in the preparation, characterization and application of gel polymer electrolytes in dye-sensitized TiO2 solar cells. A general introduction to solar cells and to polymer electrolytes will be presented in Chapter I. Chapter II describes the aims of this work. Chapter III deals with the preparation of gel polymer electrolytes based on the poly(ethylene oxide-co-2-(2-methoxyethoxy) ethyl glycidyl ether) (P(EO/EM)) polymer matrix containing I2 and different concentrations of g-butyrolactone (GBL) and LiI. These electrolyte samples were characterized by differential scanning calorimetry (DSC), Li nuclear magnetic resonance (Li RMN), thermogravimetry (TGA), X-ray diffraction (RDX), conductivity measurements and cyclic voltammetry (VC). The gel polymer electrolyte P(EO/EM)/GBL/LiI/I2 provided excellent chemical and electrochemical properties. The electrolytes were applied in dye-sensitized TiO2 solar cells, as discussed in Chapter IV. Solar cells were characterized by current-voltage (IV) curves, electron lifetime measurements and transient absorption spectroscopy (TAS). Most of the solar cells based on the polymer electrolyte P(EO/EM)/GBL/LiI/I2 presented an increase in photocurrent with the addition of GBL to the electrolyte composition. This result may be explained by the enhanced diffusion of redox species in the medium. However, a significant decrease in open-circuit voltage was observed after increasing the GBL concentration in the electrolyte composition. The decrease in open-circuit voltage was assigned to an increase in recombination losses taking place at the interfaces, which resulted in solar cells with lower performance. In order to minimize these drawbacks, dye-sensitized TiO2 solar cells were assembled with the electrolyte P(EO/EM)/GBL/LiI/I2 containing 4-tert-butylpyridine and crown ether molecules. The addition of these additives provided an increase in Voc and, consequently, improved device performance. The characterization of these solar cells based on gel polymer electrolyte containing additives was carried out by means of current-voltage (I-V) curves, as discussed in Chapter V. Dye-sensitized TiO2 solar cells based on gel polymer electrolyte were subjected to durability tests. Good durability results were achieved during a 30-day test, which are discussed in Chapter VI. Chapter VII deals with the main conclusions of this work and outlines some perspectives for the next steps of this research
Doutorado
Quimica Inorganica
Doutor em Ciências
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Smortsova, Yevheniia. "Dye sensitized solar cells efficiency improvement : optimization of the electrolyte using ionic liquids/molecular solvents mixture and study of the photodynamic properties of organic indolinic derivative dyes." Thesis, Lille 1, 2018. http://www.theses.fr/2018LIL1R061/document.
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Parmi les énergies renouvelables, l’énergie solaire est la plus puissante. L’élément clé des DSSCs est le photosensibiliseur, par lequel la génération de photocourant est possible. L’autre élément important est l’électrolyte. Les liquides ioniques (Ils) sont utilisés en tant qu’électrolytes dans les DSSCs du fait de leurs propriétés chimiques: pression de vapeur basse, haute résistance thermique et chimique, polarité et phase modulables, etc. L’objectif de cette thèse est de comprendre les processus photophysiques dans les colorants dérivés d’indolines dans les solvants moléculaires (MS) et les mélanges IL/MS. L’influence du solvant sur les propriétés spectroscopiques de D131, D102, D149 and D205 est d’abord étudiée par spectroscopie stationnaire d’absorption et de fluorescence. Ensuite, la spectroscopie résolue en temps est employée pour étudier leur photophysique et sa dépendance au solvant. Ces expériences ont permis de démontrer l’influence des paramètres d'aptitude de donneur de liaison hydrogène et d'accepteur de liaison hydrogène des solvants. Le rôle majeur de la dynamique de solvatation dans la dynamique des états excités de ces colorants a été montré. Ce phénomène a été suivi dans les mélanges IL/MS en utilisant une sonde fluorescente classique, C153, et des techniques de fluorescence résolues en temps et de dynamique moléculaire. Les réponses de solvatation multi-régimes de ces mélanges sont dirigées par le renforcement de la liaison hydrogène entre la sonde et les composants des mélanges. Les résultats de cette these apportent beaucoup à la compréhension des processus photophysiques fondamentaux régissant les sensibiliseurs et les électrolytes dans les DSSCsAmong all the renewable energy sources, solar energy is the most powerful source far ahead wind or geothermal energies. The first key component of DSSCs is the photosensitizer. It is through this component that the most important steps of photocurrent generation are possible. On the other hand, ionic liquids (ILs) have been proposed as electrolyte for DSSCs due to their peculiar properties: low vapor pressure, high thermal and chemical robustness, tunability of polarity and phase behaviour etc. The objective of this thesis was to get an understanding of the photophysics in the indoline derivated dyes in molecular solvents (MS) and in the IL/MS mixtures. Firstly, the solvent dependence of the spectroscopic properties of D131, D102, D149 and D205 was studied by the steady-state UV-Vis absorption and fluorescence spectroscopy. Then, time-resolved spectroscopy was used to elucidate their photophysics and its solvent dependence. These experiments helped to discern the influence of the hydrogen bond donor and acceptor abilities of the solvent. The solvation dynamics was shown to play a major role in the excited state dynamics of these dyes. This process in IL/MS mixtures was elucidated using the classic fluorescent probe C153 by the means of time-resolved spectroscopy and MD simulations. The complex multi-regime solvation response in these systems was shown to be shaped by the strengthening of the hydrogen bonding between the probe and the mixture components. The results of this thesis work contribute to the fundamental understanding of the photodynamics of the sensitizer and the response of the electrolyte used in the DSSCs
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Risbridger, Thomas Arthur George. "Aqueous dye sensitized solar cells." Thesis, University of Bath, 2013. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607628.
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Dye sensitized solar cells (DSSCs) have typically been produced using organic liquids such as acetonitrile as the electrolyte solvent. In real world situations water can permeate into the cell through sealing materials and is also likely to be introduced during the fabrication process. This is a problem as the introduction of water into cells optimized to use an organic solvent tends to be detrimental to cell performance. In this work DSSCs which are optimized to use water as the main electrolyte solvent are produced and characterized. Optimization of aqueous DSSCs resulted in cells with efficiencies up to 3.5% being produced. In terms of characterization, it is generally seen in this work that aqueous DSSCs produce a lower photocurrent but similar photovoltage compared to DSSCs made using acetonitrile and reasons for this are examined in detail. The decreased ability of the aqueous electrolyte to wet the nanoporous TiO2 compared to an acetonitrile electrolyte is found to be a key difficulty and several possible solutions to this problem are examined. By measuring the photocurrent output of aqueous cells as a function of xy position it can be seen that there is some dye dissolution near to the electrolyte filling holes. This is thought to be linked to pH and the effect of 4-tert-butylpyridine and may also decrease the photocurrent. It is found that there is little difference between the two types of cells in terms of the conduction band position and the reaction of electrons in the semiconductor with triiodide in the electrolyte, explaining the similarity in photovoltage. By altering the pH of the electrolyte in an aqueous cell it is found to be possible to change the TiO2 conduction band position in the DSSC. This has a significant effect on the open circuit voltage and short circuit current of the cell, though the pH range available is limited by the fact that dye desorbs at high pH values.
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Greijer, Agrell Helena. "Interactions in Dye-sensitized Solar Cells." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3752.
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Sun, Hsiao-Ting, and 孫筱婷. "Hydrogel Electrolytes for Dye-Sensitized Solar Cells." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/f6h5a6.
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碩士國立中興大學
化學工程學系所
106
In this paper, the natural material kapok fiber (Kapok Fiber, KF) is made into a film by physical crosslinking method. After the KF film absorbs the liquid electrolyte, a hydrogel state is formed. The photoconversion efficiency of hydrogel electrolyte based dye-sensitized solar cells (DSSCs) is as high as the liquid electrolyte based DSSC, while the storage stability is as well as the gel electrolyte based DSSC. The DSSCs based on the liquid and gel electrolytes were also prepared for the comparison of the PV performance of KF hydrogel electrolyte based DSSCs. The liquid electrolyte is consisting of the (valeronitrile, TBP, GUSCN, I2, LiI, PMII, and acetonitrile). The components of gel electrolytes include the PC solvent, TBP, GUSCN, I2, LiI, PMII, and hydroxyethyl cellulose (2-hydroxyethyl cellulose, HEC) The liquid electrolyte based DSSCs exhibited the photoconversion efficiency (PCE) of averages 6.05%, but its efficiency remains 30% after storage five days, which is not stability. The efficiency of the HEC gel electrolyte based DSSCs have PCE of 5.36% on average, although the efficiency is not as good as of liquid electrolyte based DSSC, the PCE of the gel electrolyte based DSSCs is still 70% after storage of five days, and the stability is quite excellent. The PCE of KF hydrogel electrolyte based DSSCs is 5.43 % on average, and the efficiency is similar to that of HEC gel electrolyte based DSSCs. After storage five days, the PCE of KF hydrogel electrolyte based DSSCs is still 80%. The stability and efficiency of KF hydrogel electrolyte based DSSCs are good. In order to improve the efficiency of the KF hydrogel electrolyte, this experiment mixed different proportions (1, 5, and 10 wt. %) of carbon nanotubes (CNT) on the kapok fiber film to increase the ion transport. After the addition of CNT, the film became solid and harder. Only the KF hydrogel electrolyte containing 1 wt.% of CNT maintained a little hydrogel state. After adding 5 and 10 wt. % of CNT, the liquid electrolyte was not easily be absorbed by the KF-CNT blend hydrogel type film. However, the presence of the CNT with good electrical conductivity results in the enhancement of the I3- diffusion coefficient in the hydrogel type film, so that the PCE of the KF-CNT film containing 10 wt.% CNT is increased upon 6.10%. In contrast, the PCE decay to only about 15% after storage five days, because the evaporation of the solvent in KF-CNT blend film based electrolyte. Therefore, the storage stability of KF-CNT blend film based DSSCs is not as good as the KF hydrogel type electrolyte based DSSCs. The liquid electrolyte based DSSC has high efficiency but its stability is not good. The efficiency of HEC gel electrolyte is slightly lower than that of the liquid electrolyte based DSSC due to the high viscosity of gel electrolyte. Higher PCE and stability were obtained for the KF-hydrogel electrolyte based DSSCs. Although the addition of CNT makes the PCE of DSSC is no different from a liquid electrolyte based DSSC, but there is still have a lot of space for improvement its poor stability.
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Yuh, Ing-Jung, and 喻映蓉. "Nano-composite Gel Electrolytes for Dye-sensitized Solar Cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/7cm4rv.
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碩士國立臺北科技大學
有機高分子研究所
102
In this study, various nanoparticles were employed to solidify 1-propyl-3-methylimidazolium iodide (PMII) based liquid electrolytes in dye-sensitized solar cells (DSSCs). A guideline to prepare high-performance clay-like or gel-like electrolytes having high content nanoparticles was prepared for DSSCs. We aimed at fabricating ionic paths between nanoparticles by chemical bondings. Photovoltaic performances of DSCs containing these quasi-solid state electrolytes were studied as well as the influence of solvents, redox couple, additives and the content of nanoparticles. Efficiencies of 4.17% was recorded for the AN-based electrolytes solidified by 35.0 wt.% ZnO nanoparticles, under illumination of simulated AM 1.5 (100mW/cm2). From the electrochemical impedance spectroscopy (EIS) analysis, it was found that the enhanced conversion efficiencies of the DSCs were associated with the decrease in charge transfer resistance at the ZnO/dye/electrolyte if we used the ZnO nanocomposite gel electrolyte.On the other hand, ZnO nanoparticles can inhibit the charge recombination, enhancing the open-circuit voltage of the cells. The DSSCs with a ZnO solidified electrolyte showed endurance of stability superior to that of a pure liquid electrolyte.
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Wang, Ying-Chiao, and 王映樵. "High Performance of Dye-Sensitized Solar Cells: MWCNTs Installed Gel Electrolytes." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/78733169996572984615.
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碩士國立臺灣大學
高分子科學與工程學研究所
99
The gel electrolytes consisting of a well-dispersed carbon nanotubes and poly(vinyidene fluoride-co-hexafluoro propylene) p(VDF-co-HFP) were prepared for the quasi-solid-state dye-sensitized solar cells (DSSCs). A structurally tailored oligomers with functionalities of poly(oxyethylene)-segmented amides and imides (POEM) was synthesized and used for dispersing multi-walled carbon nanotubes (MWCNTs). When incorporated into the p(VDF-co-HFP)-based gel electrolytes, the performance of thte quasi-solid-state DSSC had been enhanced. At 100 mW cm-2 irradiation, the short-circuit current density (JSC) and power-conversion efficiency (η) of the DSSC containing 0.25 wt% MWCNT/POEM hybrids gel electrolyte were found to reach the best performance of 15.3 mA cm-2 and 6.86%, respectively. The lowest Warburg resistance (Rw) of this DSSC was characterized by the electrochemical impedance spectra (EIS) analyses and found to be consistent with the high performance. By comparison, the corresponding values of JSC = 9.59 mA cm-2 and η = 4.63% for a DSSC based on the pristine p(VDF-co-HFP) gel electrolyte were attained as the reference. The existence of the well-dispersed MWCNT by POEM not only increase the amorphous state of the p(VDF-co-HFP) but also promote the chelating behavior to the Li+. The system further facilitates the diffusion of ion pair, I-/I3- in the electrolytes and benefits to DSSC performance. The fine dispersion of MWCNT in the gel electrolyte is essential in this system and evidenced mainly by transmission electric microscope (TEM).
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Chu, Chia-Hsien, and 朱家嫺. "Study of Solvent-Free Oligomer Electrolytes for Dye-Sensitized Solar Cells." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/34284475523512814694.
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碩士國立清華大學
化學工程學系
98
A series of polymers with ethylene oxide (EO) functional group were synthesized and analyzed as non-volatile and highly stable electrolyte for dye-sensitized solar cells (DSSCs). The oxide atoms of EO group can coordinate to lithium ions and facilitate ion-pair separation, which favors ionic conduction. In this way, polymer with EO group plays a role as not only ionic transport and reduction helper but also as “solvent,” which can dissolve ions without adding other real solvents. Meanwhile, using polymers as electrolyte take an advantage of high mechanical properties, high stability, extremely low volatility and also being favor of commercial use and so on. Compared with other solvent-free and solid-state electrolytes, this polymer electrolyte is easily synthesized and costs low. Therefore, this EO-containing polymer possesses a great potential candidate as solvent-free and solid-state electrolyte. In our study, we synthesized two novel solid-state co-polymer electrolytes (PSEO) at first, which contain Poly (methyl hydrosiloxane) (PMHS) as main back bone and Poly (ethyl glycol) methyl ether methacrylate (PEGMEMA) as side chain. To solve the high crystallization of Poly (ethylene oxide) (PEO), PMHS, which has a low Tg (Tg= -138oC), was used to modify PEGMEMA so that the ion transport can conduct favorably without solvent. Unfortunately, the viscosity of PSEO is as high as 310.48 Pa-S, about three hundred times higher than water at room temperature. High viscosity makes it difficult for ion transport, so the ionic conductivity of PSEO is only around 10-5 S/cm, which is much lower than conventional organic solvent (~10mS). In order to improve the problem of high viscosity, we used PMHS with less repeating units to obtian a new EO-containing co-polymer (NPSEO) with viscosity as low as 115.94 Pa-S. Mixing NPSEO and redox pairs together and fabricating into DSSCs to observe the cell performance and we found an unexpected results: the conversion efficiency is as low as 0.3%. To get rid of the drawback of high viscosity for solidlike polymers, we used only PEGMEMA instead of using co-polymers and form a binary electrolyte with redox pairs. The results that cell performance of PEGMEMA-based electrolytes in DSSCs presented are η= 3.51%, Jsc= 9.89 mA/cm2, Voc= 0.62 mV, ff= 0.57. Their ambient ionic conductivity is 1.16 mS/cm and the diffusion coefficient of tri-iodide dominates at around 4.98×10-7cm2/S. These two indexed can be compared to EMIBCN/PMII mixing binary ionic liquid reported or other similar PMII-doping system. After long-term stability at room temperature, the cell performance keeps at a stable condition. Except for that, we study the series EO-containing polymers in this study including viscosity, ionic conductivity and diffusion coefficient of tri-iodide and so on. In conclusion, we developed a novel solvent-free polymer-based electrolyte successfully, which has a great potential due to its high ionic conductivity, high stability and cheap properties.
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Chiang, Yu-Lin, and 江宥霖. "Study on Dye-sensitized Solar Cells Using Double Cationic Colloidal Electrolytes." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/pvjymn.
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碩士國立虎尾科技大學
電子工程系碩士班
105
The effect of electrolyte on the performance and long-term effect of dye-sensitized solar cells (DSSCs) has a significant effect. However, even if the colloidal electrolyte can lose some efficiency, it can reduce the evaporation and leakage of liquid electrolyte solvent problem. In this study, the effects of two cationic and colloidal concentrations on the performance and long-term efficiency of dye-sensitized solar cells were investigated with two different sized cationic electrolytes. The materials used for the production of the electrolytic solution are iodine (I2), lithium iodide (LII), tetrapropylammonium iodide (Pr4NI), 4-tert-butylpyridine (4-TBP), 1,2-dimethy l-3-propylimid- azolium iodide (DMPII), which is prepared by using lithium iodide as a small cation and tetrapropylammonium iodide as a large cation, and using Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and Poly (ethylene oxide) (PEO) in a weight ratio of 3: 2 ratio of the electrolyte colloidal, colloidal electrolyte will form a flow state after heating, and it can be poured into and sealed, the formation of colloid in the internal cooling and reduce the chance of exposure to air is encapsulated into dye-sensitized solar cells to measure photoelectric properties with electrochemical impedance (EIS) and compare. The open circuit voltage (VOC) of the dye-sensitized solar cell increases with the increase of the cationic content in the gelatinized electrolyte containing only tetrapropylammonium iodide, lithium iodide and iodine, and the efficiency is also dependent on the content of the large cation. The results showed that the highest efficiency was 3% when the two cations were 50% separately, and finally the same formulation was used to add 1,2-dimethyl-3-propylimidazolium iodide with 4-tert-butylpyridine to optimize the electrolyte . The efficiency shows 5.09%, the smaller cations will adsorb on the surface of titanium dioxide, helping to reduce the Fermi level, and increase the current density, but it will reduce the open circuit voltage, while the larger cation is not easy to adsorb the surface of TiO2 in improving and opening circuit voltage and ion dissociation, increasing overall efficiency.
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Mengstie, Abebe Tedla, and Abebe Tedla Mengstie. "Synthesis and Study of Unconventional Electrolytes for Dye Sensitized Solar Cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/60624450561139261047.
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博士國立臺灣科技大學
化學工程系
102
This thesis work focuses on unconventional electrolytes for both solid and liquid state DSSCs. The first part provides emphasis on the solvents of liquid electrolytes. Binary solvent system (a mixture of BMIMBr and Acetonitrile) was used to dissolve the electrolyte components in the DSSCs, aiming to combine the advantages of both solvents for the development of highly stable DSSC devices with comparable performance. Three types of electrolytes namely AY2, Z959 and a conventional one were prepared using the binary solvents with varied volume of ratio of BMIMBr. DSSC devices based on these electrolytes were fabricated. It has been found that those devices containing ionic liquid demonstrated good stabilities compared to devices composed of pure acetonitrile as a result of the substantially lower vapor pressure of the binary solvent system. The fill factor and open circuit voltage of devices with BMIMBr have shown enhancement in case of all types of electrolytes. However, short current density and conversion efficiency decreased as the amount of ionic liquid proportion increased which could be ascribed to the slow diffusion of ions. The second part of this thesis focuses on electrolytes in the solid state DSSCs. New conducting conjugated polymers (Poly(SNS-BBN, coded P2 and Poly(SNS-BBB), coded P1), that could be used as hole transporting material in ss-DSSCs, were synthesized. Devices based on these conjugated polymers were fabricated and characterized. Especially device with poly(SNS-BBB) showed reasonable open circuit voltage (0.8 V) with comparable conversion efficiency to initially reported performance of PEDOT and P3HT. Therefore, the properties and the preliminary result of these new polymers demonstrate that they are promising candidate for hole transporting material in solid state dye sensitized solar cell.
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Chen, Ying-Chu, and 陳映竹. "Nano-composite gel electrolytes for dye-sensitized solar cell." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/86609774683284818290.
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碩士國立中央大學
化學研究所
97
Quasi-solid state dye-sensitized solar cells (DSSCs) were fabricated with poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and room temperature ionic liquid (RTIL) as gel polymer electrolyte. The ionic liquids used are 1-alkyl-3-methylimidazolium iodides (RMII) and I2 are dissolved as a redox couple. Because of their wide electrochemical window, non-volatility and thermal stability, the ionic liquids are used to replace the volatile solvents. An improvement in the solvent free system is the addition of titanium oxide nano-tube (TiNT) which forms the composite polymer electrolytes with substantially improved ion conductivity. The polar fluorine groups on PVDF-HFP attract the cation of RMII and provided high degree of ion dissociation. The RMI+ would aggregate on the polymer chain and forms the ionic conducting channel. On the other hand, the surface of TiNT contains numerous oxygen groups which also can attract the RMI+. Since the structure of TiNT is orientated, self assembly of RMI+ with high degree of order is established where I- and I2 forms highly efficient redox couple. The partially ordered and oriented ion conducting channel promotes the ion diffusion and improved the ion mobility. Electrochemical analysis of the interface resistance also indicated the presence of TiNT also reduced the electrode-electrolyte interface resistance by destroying the Helmholtz double layer. As results, the photo-electronic conversion efficiency of the DSSCs was raised by adding the PVDF-HFP and TiNT to the electrolytes. The different effects of the alkyl side chain length of 1-alkyl-3-methylimidazolium iodides (RMII) on the electrochemical behavior and the photo-electronic conversion efficiency are also examined. The best performance is found with octyl side chain (C-8) where the self-assembly behavior on TiNT surface is also found to be the most prominent. On using the composite electrolyte with PVDF-HFP, TiNT and 1-octyl-3-methylimidazolium iodides (OMII), the DSSC exhibits a high energy-conversion efficiency of 4.93% under 100mW cm-2.
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Wu, Yun Ling, and 吳韻玲. "Preparation of agarose-containing quasi-solid electrolytes for dye-sensitized solar cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/59642918913028141689.
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Zhong, Si-Hua, and 鍾偲華. "Iodine-Free Nanocomposite Gel Electrolytes for QuasiSolid-State Dye-sensitized Solar Cells." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/vzx6fj.
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碩士國立臺北科技大學
有機高分子研究所
104
In this study, we tackled the corrosion and leakage problem of conventional iodine-based liquid electrolyte by developing iodine-free gel electrolytes that were solidified with metal oxide nanoparticles for dye-sensitized solar cells (DSSCs). First, two types of liquid electrolytes, with and without iodine, were prepared to investigate the influence of iodine on the photovoltaic performance of TiO2-based DSSCs. Then, three different types of metal oxide nanoparticles (ZnO, TiO2 and SiO2) were tested as gelling agents for both types of liquid electrolytes, and the photovoltaic performance of resulting DSSCs were investigated. The results show that removing iodine from the electrolyte markedly reduced the FF value, leading to lower overall conversion efficiency (from 7.37% to 6.94%), despite a small improvement in the short-circuit current density (JSC) brought about by the lower absorbance of the I2-free electrolyte. Of the three types of nanoparticles tested, TiO2 yielded best results. Under simulated full sunlight (AM1.5, 100 mW/cm2) the I2-free quasi-solid state DSSCs solidified with 10 wt% of TiO2 nanoparticles achieved 8.07% power conversion efficiency, a 16% improvement compared with what attained by the quasi-solid state counterpart. The increase in the power conversion efficiency was due to higher JSC and open-circuit voltage (VOC). The former can be attributed to reduced charge-transfer resistance at the TiO2/dye/electrolyte interfaces and the diffusion resistance of the electrolyte, while the enhancement in VOC was due to decreased charge recombination. Durability studies show that quasi-solid state DSSCs had higher stability than the liquid electrolyte counterparts. Also, the I2-free devices outperformed those contained I2, indicating removing I2 from the electrolyte could improve DSSC stability. The I2-free 10%-TiO2 devices showed excellent at-rest stability, retaining more than 95% of their peak efficiencies after 1000 h of storage at room temperature in darkness. When the cells were exposed to 65% relative humidity at 65 °C, the failure time was determined to be ca. 1200 h, corresponding to a lifetime of 5-6 years at room temperature.
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Tseng, Lin-Chieh, and 曾麟傑. "Imidazole-containing Hyperbranched Polymer Based Gel Electrolytes for Dye Sensitized Solar Cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/76482527906865617441.
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碩士國立中興大學
化學工程學系所
102
In this study, imidazole-containing X-shaped oligmer (PEI) and hyperbranched polymer (CPEI) were synthesized. Chemical structures of PEI and CPEI were confirmed by 1H-NMR. TGA results indicate that high thermal stability were observed for PEI and CPEI. Two electrolyte formulation systems were prepared for dye-sensitized solar cells (DSSCs). For first system, 4 wt %, 8 wt %, 15 wt % of PEI or CPEI were dissolved in ionic liquid (PMII/EMIBF4 = 13：7, v/v) electrolyte to form X-shaped oligmer and hyperbranched polymer containing ionic liquid type gel electrolytes. No volatile organic solvent was added in this type of electrolyte. For the second system, 4 wt %, 8 wt %, and 15 wt % of CPEI were dissolved in 3-methoxypropionitrile (MPN) solvent based electrolyte to form the solvent-based hyperbranched polymer containing gel electrolytes. Ionic conductivity and limiting diffusion current analysis were measured for these ionic liquid type and MPN solvent based polymer gel electrolytes . N719 dye based DSSCs incorporating with the ionic liquid type and MPN solvent based polymer gel electrolytes were fabricated. Electrochemical impedance spectroscopy (EIS) and photovoltaic (PV) performance were measured. The results indicate that the DSSC devices fabricated from PEI and CPEI doped gel electrolytes exhibited higher charge-transfer resistances (Rct2) values at the interface of TiO2/dye and electrolyte. High resistance suppressed would suppress the dark current, therefore higher electron lifetimes for recombination in the TiO2 film were obtained for the samples with 4wt% of PEI (PCE = 5.86%) and CPEI (PCE = 5.62%). In addition, a high PCE value (7.18%) was obtained for the DSSC fabricated from the 4wt% CPEI doped MPN solvent-based gel electrolyte. Apart from that, the operational stabilities of the DSSCs were also investigated. The PEI and CPEI doped ionic liquid gel electrolyte based DSSCs showed much better operational stability than did the CPEI doped MPN solvent type electrolyte based DSSCs.
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Chen, Po-Kai, and 陳博楷. "I. Preparation of Iodine-Free Nanocomposite Gel Electrolytes for Dye-Sensitized Solar Cells II. Nanosheet-based Zinc Oxide Microspheres for Dye-Sensitized Solar Cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/4gd6rg.
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碩士國立臺北科技大學
有機高分子研究所
105
In this study, Iodine-Free dye-sensitized solar cells (DSSCs) are fabricated using gel electrolytes with polymer (Polyvinylidene difluoride PVdF) and nanoparticles (TiO2), the gel electrolytes solved the problem of corrosion from I2. However, the ion-diffusivity and conductivity of gel electrolytes decrease when increasing PVDF concentration. Substituted 3-Methoxypropionitrile(MPN) by propane-nitrile (PPN) as solvent, the PPN based gel electrolytes DSSCs with energy conversion efficiency (7.84%) higher than the MPN based gel electrolytes (7.06%).、 In the other case, multiple-shelled ZnO microspheres are fabricated by a hydrothermal method. The multiple-shelled ZnO microspheres have a favorable concentration of the adsorbed dye that can improve the light penetration for DSSCs.
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Chen, Ssu-han, and 陳思涵. "Dye-Sensitized Solar Cells with Ferrocene-Based Electrolyte." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/11649803337925495057.
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碩士國立中央大學
化學研究所
100
Dye-Sensitized Solar Cells (DSSCs), one of the third generation thin film solar cells, are attractive due to their low cost, light weight, colorfulness, easy fabrication and flexibility. Electrolyte is one of the important components, which reduced the dye, carried the hole to the cathode and determine the Voc of a DSSC. Iodide/ triiodide system is the commonly used electrolyte, however it has some inherent drawbacks. Looking for other alternative electrolytes become an active research. Ferrocene/ Ferrocenium system with non corrosive in nature, low redox potential, and high redox reactivity has a great potential to be used as a electrolyte material in DSSC. In this study, We used two dyes: one is Ru-complex CYC-B12 developed by our laboratory, and the other is organic dye D149 as sensitizers. TiO2 electrode was pretreated by TiCl4 before dye adsorption. Electrolyte with arious components as well as different ratio of each component were used to explore the performance of DSSC based on ferrocene/ ferrocenium electrolyte. The best one is K33 electrolyte with the composition of 0.1M ferrocene/ 0.01M FcBF4/ 0.1M TBP/ 0.2M LiTFSI/ 0.06M TBACDCA in ACN. DSSC used K33 electrolyte, CYC-B12 sensitizer achieves the efficiency of 3.49 % (I-/I3- system：6.87 %). When D149 dye was used the efficiency of DSSC based on the same TiO2 anode and K33 electrolyte is 4.04 % (I-/I3- system：5.81 %).
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Hsu, Hsin-Ling, and 徐幸鈴. "Agarose gel electrolyte-based dye- sensitized solar cells." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/67897205511291187706.
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博士國立交通大學
材料科學與工程學系所
102
Dye-sensitized solar cell (DSSC), a new generation organic solar cell, has tremendous market potential due to its low cost, flexibility as a device, and indoor usage. Recently, gel electrolytes are highly pursued for DSSCs because of its better ion transport ability than the solid electrolyte and its better stability than liquid electrolyte. Moreover, natural materials such as polysaccharides have been attempted to gel the liquid electrolytes of DSSCs to prevent environmental pollution. In this thesis, a natural agarose is chosen as the matrix of the gel electrolytes, whose performance and the efficiency of DSSCs still require much improvement compared to liquid electrolytes. Furthermore, three approaches were employed to enhance the performance of aragose gel electrolyte-based DSSC: (1) using environmentally benign solvents, (2) utilizing the low viscosity ionic liquids, and (3) modifying the pore size of TiO2 films. On the environmentally benign solvents, the electrolyte containing the co-solvent of 80 vol.% propylene carbonate (PC) and 20 vol.% dimethyl sulfoxide (DMSO) yielded the highest conductivity, 14.2 mS cm-1, and the highest diffusion coefficient of triiodide, 2.7×10-6 cm2 s-1. Its conversion efficiency with agarose was of 3.4%, which retained ~80% of the energy conversion efficiencies of the reference cell without agarose. Yet, it was 2.4 times improvement compared to pure 1-methyl-3-propylimidadolium iodide (MPII) with agarose (1.4%) under the illumination at AM 1.5, 100 mW cm-2. The efficiency of the DSSC using the agarose gel electrolyte containing ionic liquid, 1.5 M 1-allyl-3-ethylimidadolium iodide (AEII) and 0.65 wt% agarose is 5.89 % with the highest I3- diffusion coefficient of 7.7×10-6 cm2 s-1. The performance of the AEII ionic liquid-based agarose gel electrolyte is comparable to the liquid electrolyte based on 3-methoxypropionitrile (MPN) (5.84 %). Finally, Using the optimized TiO2 film with larger pores (30% PEG loading, 100 °C /60 min), an efficiency of 7.43% is achieved for the agarose gel electrolyte-based DSSC, which represents a 26.1% improvement over TiO2 without the addition of PEG. The approaches mentioned above have made the performance of agarose gel electrolyte higher than the MPN-based electrolyte.
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Song-ChuanSu and 蘇頌傳. "Preparations of Printable Electrolytes for Dye-Sensitized Solar Cell Applications." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/u22bq6.
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碩士國立成功大學
化學工程學系
102
The aim of this study is to develop a novel printable electrolyte to apply on Dye-Sensitized Solar Cells (DSSCs) modules fabrication. To meet the requirements of printing manufacturing process, low volatility solvent gamma-Butyrolactone (gBL) is employed to prepare printable electrolyte using polyacrylonotrile (PAN) as the viscous agent. Experimental results show that, gBL liquid electrolyte with 12wt% PAN has the optimum printing viscosity 37.3 Pa·s, in which device power conversion efficiency (PCE) 7.04% can be reached. Moreover, viscous electrolyte is easier to penetrate into TiO2 meso-porous matrix by using printing process instead of injection process. In order to enhance the performance of printable device, the effect of TiO2 and TiC nanoparticles is investigated respectively. The results show that, although the addition of TiO2 nanoparticles raises the device PCE, the problem of dye-desorption induced by the TiO2 nanoparticles dispersion in the electrolyte occurs. Such problem is overcome by substituting TiC nanoparticles for TiO2 nanoparticles. A great improvement is observed by adding TiC nanoparticles in the stability test, in which the PCE raises to 7.45%. Such printable devices can maintain 94% of its initial efficiency under room temperature after 600 hour stability test. Furthermore, the study successfully applies printable electrolyte to DSSC modules, and the PCE of 4.11% can be obtained.
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Wang, Fang-Yi, and 王渙昱. "Alkoxysilane Modified Hydroxyethyl Cellulose Based Polymer Gel Electrolytes for Dye Sensitized Solar Cells." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/78838684304282646151.
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碩士國立中興大學
化學工程學系所
105
In this study, a series of polymer gel electrolytes based on the alkoxysilane interlinked celluloses (C-S) were prepared and application for the dye-sensitized solar cells (DSSCs). The C-S samples have been synthesized by the sol-gel reaction of cellulose (HEC) and (3-aminopropyl)trimethoxysilane (APTMS). Using different molar ratios of HEC and APTMS (1:3, 1:6, 1:9, and 1:12) to synthesize a series of polymers (CS13, CS16, CS19, and CS112). 10wt% of CS13, CS16, CS19, and CS112 were dissolved in the I2, LiI, TBP, PMII, and GuSCN containing propylene carbonate solution and used as the gel electrolytes of DSSCs. The viscosity of the polymer electrolytes was decreased with the content of APTMS. The formation of silicate based inorganic network was confirmed by the 29Si-NMR spectroscopy. Better photovoltaic parameters were observed for the DSSC based on the C-S sample with higher APTMS content. In contrast, better stability of photovoltaic performance was obtained for the DSSC based on the C-S sample with lower APTMS content
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Chen, Huang-yu, and 陳皇宇. "The study of the electrolytes applied in dye-sensitized solar cell." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/78765134584135484970.
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碩士國立高雄第一科技大學
光電工程研究所
97
This study investigates the effects of electrolytes on dye-sensitized solar cell. Prepare various electrolytes with different compositions and concentrations by utilizing the materials in our laboratory. Then, discuss the effects of various electrolytes on open circuit voltage (VOC), short circuit current (ISC), fill factor (F.F.), and efficiency conversion (η) of dye-sensitized solar cell, and find out the optimum composition of the electrolyte. The working electrode of dye-sensitized solar cell is coated with TiO2 thin film on a FTO-glass substrate, and then sintered by high temperature furnace, which immersed into N-719 (Ruthenium) solution at 70℃ for 6 hours. In addition, prepare a FTO-glass substrate to plate with a Pt layer on as a counter electrode. Finally, the dye-sensitized solar cell is assembled, and the VOC, ISC, F.F., and η of DSSC are measured by using Science Tech 150W I-V measurement system. No matter choose 3-methoxypropionitrile (MPN) or 3-propylene carbonate (PC) as solvent, we can find that ISC improve as the concentrations of Li+ ions increase and VOC decreases slightly as the concentrations of Li+ ions increase. If MPN is chosen as solvent, the conversion efficiencies are low because that the powder of KI can’t be dissolved completely, which the best efficiency is 2.45% when the concentration Li+ is 0.3 M. If PC is chosen as solvent, the conversion efficiencies are higher than before, which the best efficiency is 3.13% when the concentration Li+ is 0.2 M.
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You, Chang-Feng, and 游長峯. "Liquid crystal-doped liquid electrolytes for dye-sensitized solar cell applications." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/7k7k8u.
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博士國立彰化師範大學
光電科技研究所
105
We investigate the effects of liquid crystal (LC) dopant on the power conversion efficiency (PCE) of dye-sensitized solar cell (DSSC). The photovoltaic and electrochemical impedance spectra indicate that minute amounts of LC dopant decrease the short-current density of DSSC because the doped LCs reduce the electrochemical reaction rate between DSSC counter electrode and electrolyte. The doped LC impedes the degradation rates of DSSC because of the interaction between cyano groups of the doped LCs and organic solvent in the liquid electrolyte. Owing to the molecular interaction, the doped LCs increase the viscosity and stability, thereby inhibiting the evaporation rate of the liquid electrolyte. Next, the commercialized LCs are also doped into the DSSC. Results indicate that the polar fluoro groups of the commercialized LCs effectively interact with the cyano groups of the organic solvent in the liquid electrolyte, enhancing the long-term stability of the DSSC but without significantly reducing PCE of the DSSCs. The viscosity of the LC dopant is a key factor that affects the light–to–electrical energy conversion efficiency of the LC-doped DSSC. The short-current density and related PCE of the DSSC is not reduced because of the low viscosity of the doped fluorinated carbon-based LCs.
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Yu, Yi-Sian, and 余奕賢. "Gel State and Quasi-Solid State Electrolytes of PolydimethylbenzimidazoleApplied in Dye Sensitized Solar Cells." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/18643366103593710525.
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碩士國立中山大學
光電工程學系研究所
100
In this research, gel-state and quasi-solid state dye-sensitized solar cells (DSSCs) were fabricated with polydimethylbenzimidazole(PDMBI) as the polymer electrolyte. These devices are stable under room light in air, even without encapsulation. The energy conversion efficiency of gel-state cells was drastically increased around 200% after the device worked. We propose that appropriately aggregated PDMBI in electrolyte layer could provide pathways which would facilitate the diffusion of ion through the electrolyte. Moreover, this arrangement induces it an ion exchange reaction which could lead to the promotion of the diffusion rate between iodide species. An optimized device performs well with a power conversion efficiency of 4.98% under air-mass 1.5 global (AM 1.5G) illumination. For the fabrication of quasi-solid state dye-sensitized solar cells, we immersed a few liquid electrolyte to improve electrical contact between TiO2 porous layer and PDMBI layer. The quasi-solid state cell efficiency fabricated with PDMBI as electrolyte was 2.26%. Furthermore, our device architecture is performing well because of the good band alignment among TiO2, dye, and PDMBI. In this research, we have successfully demonstrated gel-state and quasi-solid state dye-sensitized solar cells comprising PDMBI as electrolyte.
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Mathew, Ambily. "Nanocrystalline Titania Based Dye Sensitized Solar Cells - Effect Of Electrodes And Electrolyte On The Performance." Thesis, 2012. http://hdl.handle.net/2005/2451.
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Dye-sensitized solar cells (DSC) have attracted considerable scientific and industrial interest during the past decade as an economically feasible alternative to conventional photovoltaic devices. DSCs have the potential to be as efficient as silicon solar cells, but at a fraction of the cost of silicon solar cells. The unique advantage of DSC compared to conventional solar cells is that the light absorption, electron transport and hole transport are handled by different components which reduces the chance of recombination. In the present work, to facilitate DSC with good energy conversion efficiency, its performance have been evaluated as a function of titania layer morphology, redox couple concentration and the catalytic layer on the counter electrode. The results that are obtained in the present investigations have been organized as follows
Chapter 1 gives a brief exposure to DSC technology. Special emphasize has been on the structure and individual components of the DSC.
Chapter 2 describes various experimental techniques that are employed to fabricate and characterize DSCs under study.
Chapter 3 presents a systematic study of the characteristics of DSC made of three different types of electrodes namely: TiO2 nanotubes (TNT) which have excellent electron transport properties, TiO2 microspheres (TMS) which possess high surface area and light scattering ability and TiO2 nano particles (TNP) possessing high surface area. The electronic, morphological, optical and surface properties of individual electrodes are studied. The highest efficiency of 8.03% is obtained for DSCs prepared with TMS electrodes. A higher value of effective diffusion coefficient (Deff) and diffusion length (Ln) of electrons as obtained by electrochemical impedance spectroscopy (EIS) analysis confirms a high charge collection efficiency in microsphere based cell.
Chapter 4 gives a detailed study of DSCs fabricated with a tri-layer photo anode with TNTs as light scattering layer. The tri-layer structure has given an enhanced efficiency of 7.15% which is 16% higher than TNP based cell and 40% higher than TNT based cells.
Chapter 5 deals with the investigations on the effect of concentration of redox couple on the photovoltaic properties of DSC for different ratios of [I2] to [LiI] (1:2, 1:5 and 1:10) with five viii concentrations of I2 namely 0.01 M, 0.03 M, 0.05 M, 0.08 M and 0.1M in acetonitrile. It is found that the open circuit potential (Voc) decreases with increase in the ratio of redox couple whereas short circuit current density (Jsc) and fill factor (FF) increase. The reason for the decline in Voc is the higher recombination between electrons in the conduction band of TiO2 and the I3- ions present in the electrolyte, induced by the absorptive Li+ ions. In addition using EIS it is found that the τ improves with the increase in [LiI] at a particular [I2], whereas at a fixed [I2]/ [LiI] ratio the increase in [I2] is found to reduce the τ and Deff due to the enhanced recombination.
Chapter 6 describes the application of carbon based counter electrode (CE) materials for DSCs. Two counter electrode materials have been investigated namely (1) Multiwalled carbon nanotubes (MWCNT) synthesized by pyrolysis method and (2) Platinum decorated multiwalled carbon nanotubes (Pt/MWCNT) prepared by chemical reduction of platinum precursors. Using Pt/MWCNT composite electrode the DSC achieved an energy conversion efficiency of 6.5 %. From the analysis on symmetric cells, it is found that electro catalytic activity of Pt/MWCNT CE is similar to that of platinum CE, though the platinum loading is very less for the former. This is attributed to the effective utilization of catalyst owing to high surface area arising from the increased surface roughness.
Chapter 7 discusses the application of titanium foil in place of glass substrate for the photo anode. The titanium foil offers fabrication of flexible DSC. The performance of DSC with TMS layers and aligned titania nanotube arrays (TNA) prepared by anodization method is studied. Compared to TMS based cell, TNA has given a better efficiency at a lower thickness.
Chapter 8 presents the scheme used to seal DSCs and its stability analysis. We have employed the usual hot melt sealing for edge whereas hole sealing is carried out with tooth pick and a UV curable adhesive. The degradation in efficiency is found to be 20% for low efficiency cells whereas, for high efficiency cells it is found to be 45% after 45 days. The leakage of highly volatile acetonitrile through the edge and hole is found to be responsible for the reduction in the performance of the device. Hence a high temperature sealing method is proposed to fabricate stable cells.
Chapter 9 gives summary and conclusions of the present work
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Hsu, Po-Ya, and 許博雅. "Fabrication of Highly Efficient Flexible Dye-sensitized Solar Cells Based on Quasi-solid State Electrolytes." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/30515502312568114242.
Full textAbstract:
碩士國立清華大學
工程與系統科學系
99
In this study, several attempts have been made to fabricate highly efficient flexible dye-sensitized solar cells based on quasi-solid state electrolytes. Ionic gel electrolytes by dispersing various nanoparticles or polymers into ionic liquid electrolytes and assembled DSCs were prepared. The DSCs device based on the ionic gel electrolyte solidified by TiO2 nanoparticles yielded the best performance. Three different kinds of the titanium dioxide (20nm pure anatase, P25 and ST01) were dispersed in solvent to prepare binder-free nanocrystalline TiO2 pastes. Incorporation of large nanoparticles (100 nm) has been employed as light-scattering centers to increase the optical length in the film, and an enhanced light-harvesting has effect by scattering. A static mechanical compression technique as the post-treatment is employed to the flexible ITO/PEN photoelectrodes in order to enhance the particles connection. The construction of the film was optimized to elicit high photovoltaic performance. Effect of the loading of TiO2 thickness of TiO2 film on the photovoltaic performance was first investigated with the sensitizer N719 in combination of TiO2 solidified quasi-solid electrolyte. A solar cell with platinum-coated FTO glass counter electrode and ITO/PEN photoelectrode, prepared by an ethanol based low-temperature TiO2 paste composed of a mixture of P25 (21nm, 25% rutile and 75% anatase) and 100 nm anatase TiO2 particles, yielded highest conversion efficiencies of 6.53% under 1 sun illumination. All plastic DSCs are also investigated by applying Pt-sputtered or Pt-spread ITO/PEN counter electrodes. The all plastic DSC with Pt-sputtered ITO/PEN counter electrode yields a light to electricity conversion efficiency of 4.67% under 1 sun illumination.
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Huang, Kuan-Chieh, and 黃冠傑. "On the Composite Counter Electrodes and Quasi-Solid-State Electrolytes for Dye-Sensitized Solar Cells." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/29598026080233046186.
Full textAbstract:
博士國立臺灣大學
化學工程學研究所
100
The exploration of solar energy is one of most intensive studies on the technologies of green energy in recent years. A new generation of solar cell, dye-sensitized solar cell (DSSC), has been investigated worldwide due to the advantages, including facile development of cell, flexibility, and colorful appearance. In terms of (1) improving the power-conversion efficiency (η) of cell (Chapter 3), (2) reducing the consumption of fabrication of cell (Chapter 4 and Chapter 5), and (3) enhancing the long-term durability of cell (Chapter 6 and Chapter 7), various nanomaterials have been synthesized and prepared for the counter electrodes (CEs) and the electrolytes of the DSSCs in this dissertation. For improving the η of DSSC, a conducting glass substrate spin-coated with a composite thin film, consisting of platinum nanoparticles (PtNPs) and multi-wall carbon nanotubes (MWCNTs), is prepared for a CE of a DSSC (Chapter 3). A homemade polymer, poly(oxyethylene)-segmented imide (POEM), is used and served as stabilizer and dispersant for MWCNTs in the aqueous solution. The best electro-catalytic ability of the film for the reduction of tri-iodide (I3-) ions is obtained after the film is annealed at 390 oC. This is attributed to the complete decomposition of non-conducting POEM, to the formation of PtNP with a moderate crystalline size, and to the surface roughness of film. Thus, an η of 8.47 ± 0.21% of the DSSC with the CE based on the composite film shows much higher than that of a DSSC applying a Pt-coated CE (η = 7.41 ± 0.24%) under illumination of 100 mW cm-2. For reducing the consumption of fabrication of DSSC, an electro-polymerized composite thin film consisting of nanographites (NGs) and polyaniline (PANI) on the conducting glass substrate is prepared for the replacement of costly Pt as the CE of a DSSC (Chapter 4). A well dispersing ability of NG/aniline particles in the depositing solution is obtained after the particles are treated by reflux-condensation; thereby improving the depositing quality of NG/PANI composite film on the substrate by electro-polymerization. The fine distribution of NGs in the film results in an enhanced conductivity of it, with reference to the conductivity of pristine PANI film. Thus, a percentage of 98.3%, corresponding to the η of a DSSC made of Pt-coated CE, for the DSSC with the NG/PANI CE is acquired. The competitive electro-catalytic ability of the film in comparison to that of film of Pt is confirmed by scanning electrochemical microscopy. In addition, hollow spherical PANI (hsPANI) particles are also deposited on the conducting glass substrate by means of reflux-condensation and electro-polymerization for the CE of a DSSC (Chapter 5). A larger active surface area (A) of thin film consisting of hsPANI particles is estimated to be 0.191 cm2, with reference to that of pristine PANI film (A = 0.126 cm2) by rotating disk electrode. The increased A is beneficial for the reduction of I3-. Thus, a percentage of 95.4%, corresponding to the η of a DSSC with a Pt-coated CE, for the DSSC made of hsPANI CE is obtained. The film consisting of hsPANI particles can serve as a potential alternative for the replacement of Pt catalyst on the CE. For enhancing the long-term durability of DSSC, a liquid electrolyte based on organic solvent is converted into a quasi-solid-state electrolyte by the gelation using a polymer, poly(vinyidene fluoride-co-hexafluoro propylene) (PVDF-HFP), for a DSSC (Chapter 6). The crystallinity of PVDF-HFP decreases when high thermal stable nanoparticles of aluminum nitride (AlN) are incorporated in the quasi-solid-state electrolyte. Thus, the diffusion coefficient of iodide (I-) is increased from 2.97 × 10-6 to 3.52 × 10-6 cm2 s-1. Under 1 sun illumination, the η of a DSSC with this quasi-solid-state electrolyte gives a higher value of 5.27 ± 0.23%, compared to that of a DSSC without adding AlN in its electrolyte (η = 4.75 ± 0.08%). Merely a loss of 5% in η of the DSSC with reference to its initial η is observed for the at-rest durability of the quasi-solid-state DSSC in a period of 1,000 h. In addition, a solvent-free ionic liquid (IL)-based electrolyte containing a synthesized composite of MWCNT/crown ether is prepared for a quasi-solid-state DSSC (Chapter 7). An IL, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4), is used. Prior to the characterization of performance for the DSSC with this IL electrolyte, crown ether, 15-crown-5, is preferably chosen owning to its appropriate size of cavity for capturing the lithium (Li+) in the electrolyte in comparison to the capturing abilities of 12-crown-4 and 18-crown-6. Thus, the decrease in electrostatic force between Li+ and I- leads to an improvement of the exchange reaction of I- and I3- by adding the MWCNT/15-crown-5 composite in the EMIBF4 electrolyte. The transport of electrons is facilitated by MWCNTs. Consequently, the values of short-circuit current density and η of the DSSC with both MWCNT/15-crown-5 and EMIBF4 in its electrolyte exhibits increases by 71.2 and 38.8%, respectively, with reference to these values of a DSSC with a bare EMIBF4. The at-rest durability of this quasi-solid-state DSSC is found to be unfailing for a period of 1,200 h.
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Shiu, Shiao-Long, and 許曉壟. "Investigation of Graphene-Based Gel-State Electrolytes and Counter Electrodes for Dye-Sensitized Solar Cells." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/8pvxgv.
Full textAbstract:
碩士國立東華大學
光電工程學系
106
Dye-Sensitized Solar Cells (DSSCs) have attracted much attention due to their various merits, such as relatively high efficiencies, simple device structures, easy fabrication, and low cost. These features have made DSSCs attractive for solar energy applications in the face of increasing energy and environmental challenges. However, the problems of electrolyte's sealing, corrosion, thus lack of stability and the cost of Pt isrelatively expensive limit the commercialization of DSSCs. There are three parts in this study. First, we added the graphene, the lithium bis(trifluoromethanesulphonyl)imide, and camphorsulfonic acid into PMMA gel-based electrolytes, and the properties of the DSSCs were analyzed by J–V, IPCE, electrochemical impedance, and stability measurements. The highest power conversion efficiency of 8.46% was recorded for quasi-solid-state DSSCs with 0.05M Li bis, 0.05M CAS and 1.3mg/ml graphene . Second, the TiO2 nanoparticles and the graphene are employed to solidify an acetonitrile-based liquid electrolyte for DSSCs, and the properties of the DSSCs were analyzed by J–V, IPCE, electrochemical impedance, and stability measurements. The highest power conversion efficiency of 8.87% was recorded for quasi-solid-state DSSCs with 10.0 wt% TiO2 nanoparticles and 1.3mg/ml graphene as the gelator. Third, nanocomposite materials of GO and marcrocyclic Yb complex were prepared. The electrode properties and device efficiency were analyzed. The DSSCs fabricated with the rGO/Yb (1:10) CE exhibited a power conversion efficiency of 7.9%, which was higher than that of the Pt counter electrode.
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Ho, Yu-Sheng, and 何宇勝. "Study of dye-sensitized solar cell using cholesteric liquid crystals embedded electrolytes." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/31074503205962488579.
Full textAbstract:
碩士國立中山大學
光電工程學系研究所
99
The study proposed a high efficient dye sensitize solar cell (DSSC) by embedding liquid crystal in liquid electrolyte. When liquid crystal molecules was disperse in the liquid electrolyte, the light-scattering occur due to refractive index mismatching by randomly oriented liquid crystal droplets. The light-scattering allows solar light have longer optical path length within the solar cell and therefore enhances light-trapping efficiency of N719 dye. The experiment results reveal that the DSSC with the liquid crystal concentration of 20 wt% have best electric conversion efficiency. Moreover, the study also introduces chloseteric liquid crystal to the liquid electrolyte of a DSSC and compare with nematic liquid crystal embedded DSSC. The cholesteric liquid crystal with periodic helical structure in the liquid electrolyte provides not only light-scattering but also selective reflection. Compared with nematic liquid crystal embedded DSSC, the cholesteric liquid crystal embeded DSSC has a more large light-trapping efficiency due to combined effects of light scattering and selective reflection. Besides, when the reflective band (480~580nm) of cholesteric liquid crystal is matched to the absorption spectrum of N719 dye, the DSSC has better photoexcitation of dye and photovoltaic performance.
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Jian-CiLin and 林建錡. "Preparation of High-performance Printable Electrolytes for Dye-sensitized Solar Cell Applications." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/99v97s.
Full textAbstract:
碩士國立成功大學
化學工程學系
105
In this study, printable electrolytes containing I-/I3- redox couples are developed with N719 dye for dye-sensitized solar cell (DSSC) applications. 3-methoxypropionitrile (MPN) is employed as a solvent with low volatility in order to reduce the electrolyte evaporation during the fabrication of solar cells. Two kinds of polymers, poly (ethylene oxide) (PEO) and poly (methyl methacrylate) (PMMA), are added simultaneously into electrolytes to regulate the viscosity achieving the requirement of printing. The results show that PEO is the required material to form the electrolyte paste, and the addition of PMMA can increase the ionic conductivity of the electrolyte to improve cells performance. However, a higher ratio of PMMA will lead to low viscosity of the electrolyte which is not proper to operate the printing process. The experimental results show that the optimal PEO/PMMA ratio and the overall polymer amount in an electrolyte are respectively 7:3 and 9 wt% with a limited viscosity of 16.94 Pa⸱s. The DSSC using this printable electrolyte can achieve a power conversion efficiency (PCE) of 8.49% under standard 1 sun irradiation (100 mW/cm2). Also, the viscous electrolyte performs an excellent penetration into TiO2 meso-porous matrix by using printing process, leading to higher open-circuit potential. When 10wt% TiO2 nanoparticle is introduced to the printable electrolyte, the PCE can further increase to 9.12%, which is much higher than that of the liquid cell. In addition, the DSSC employing printable electrolyte displays a stable photovoltaic performance during the aging test at 60 °C for 500 hours. By adjusting the thickness of TiO2 film, a power density (Pmax) of 10.65 μW/cm2 is obtained for the cells under 200-lux illumination. Furthermore, the printable electrolytes are applied to sub-module device under different light irradiation; a PCE of 6.78% and a Pmax of 8.68μW/cm2 are achieved under 100 mW/cm2 and 200-lux illumination respectively.
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Yu, Hsiao Ju, and 俞曉茹. "Nanoparticles doped polymer gel electrolyte for dye-sensitized solar cells application." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/17769582117509764897.
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Shou-ChenKao and 高守辰. "Performance Enhancement of Gel-State Dye-Sensitized Solar Cells by Composition Regulations of Gel-State Electrolytes." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/18247107860002245570.
Full textAbstract:
碩士國立成功大學
化學工程學系碩博士班
100
In this study, the gel-electrolyte, which use poly acrylonitrile – vinlyacte (PAN-VA) or Poly vinylidenefluoride−co− hexafluoropropylene, (PVDF−HFP) as the gelator, are compared. The characteristic of gel-electrolyte ,and the efficiency and stability of DSSC are investigated by increasing the amount of polymer, mixing high-boiling point solution, and adding TiO2 nano-particle. As results, the DSSC with PAN-VA as gelator have better cell performance than the one with PVDF-HFP. Furthermore, the electrolyte with Acetonitrile (ACN) as solvent and when the percentage of PAN-VA in the electrolyte increase from 7% to 15%, the ion-conductivity of electrolyte decreased, the phase-transfer temperature could be increased from 35 oC to 40 oC. The efficiency of the cell is between 7.18% ~7.14% with non-significant difference. Moreover, by mixing high-boiling point solvent, 3-Methoxy–propionitrile (MPN), as the co-solvent of electrolyte could increase the phase-transfer temperature of co-solvent gel-electrolyte and increase the stability of DSSC. However, the efficiency of the cell may decrease. Furthermore, adding TiO2 nano-particle could increase the phase-transfer temperature of electrolyte to over 65 oC. The efficiency of the cell could be raised over 8% and the stability at 60 oC could be held over 500 hours.
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Chen, Hsin-Yi, and 陳欣怡. "Study on Improving Performance of Dye-Sensitized Solar Cells by Inorganic Layered Materials in Luquid Electrolytes." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/90709441655640698354.
Full textAbstract:
碩士中原大學
化學研究所
101
Dye-sensitized solar cells (DSSCs) using a liquid electrolyte that could cause a high conversion efficiency; however, leakage of the liquid electrolyte has a negative impact on the cell stability. The literatures indicate that using nanoparticles in electrolyte can enhance the performance of the cells and improve the leakage problems effectively. In this study, there are eleven different types of inorganic layered materials which represent tetrahedral substituted smectites or octahedral substituted smectites, different cation exchange capacity (CEC), different metal ions located between the layers, pure and modified clay, and layered double hydroxide (LDH) .These eleven types of inorganic layered materials added in the liquid electrolyte, and then compared their photo-to-current conversion efficiency. According to the experiment, device open-circuit-voltage (Voc) could be improved effectively when the clay adding amount is 5wt%, the optimum value of the photocurrent is included, and get the best conversion efficiency. It gets the best dispersed, high viscosity, and much more convenient in seal compared with liquid electrolyte and there is little leakage problem when we chose the clay with tetrahedral substituted in liquid electrolyte. Adding tetrahedral substituted nanoclay with liquid electrolyte could increase the conversion efficiency significantly from 6.72% to 7.15% and limiting current and tri-iodide ion diffusion coefficient can also be increased when adding tetrahedral substituted nanoclay in liquid electrolyte. The CL5-5% + AN diffusion impedance is also lower by the Electrochemical Impedance Spectroscopy(EIS). For long-term stability test the adding CL5-5% + AN electrolyte could be better stability compared with the pure liquid electrolyte either at room temperature or at heated state.
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Yang, Shun-Siang, and 楊舜翔. "Application of Different Plasticizers for the Gel-state Electrolytes Used in the Dye-sensitized Solar Cells." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/32cvne.
Full textAbstract:
碩士國立臺北科技大學
有機高分子研究所
99
Gel-state electrolytes have been prepared using 0.6M NaI + 0.06M I2 + 0.5 M tert-butylpyridine + 8-10％poly(vinylidenefluoride-co-hexafluoropropylene) [PVDF-HFP] with different plasticizers -acetonitrile、propylene carbonate and mixture of acetonitrile and propylene carbonate . The dye-sensitized solar cells (DSSC) have been assembled from anode containing Anatase TiO2 absorption and diffraction layers with N719 dye, Pt cathode and above gel-state electrolytes. The best photoelectric conversion efficiency (η=7.53％)was obtained from DSSC prepared with gel-state electrolyte of acetonitrile and 9％ PVDF-HFP.The second one (η=7.3) was from DSSC with gel-state electrolyte of the mixture of acetonitrile (9) and propylene carbonate (1) and 7％ PVDF-HFP. These DSSC conversion efficacies were about 86-89％ relative to that of DSSC using the same electrolyte without PVDF-HFP polymer.
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Li-TungChen and 陳立東. "Preparation of Cobalt-based Gel-state Electrolytes for Dye-Sensitized Solar Cell Applications." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/03082196405385173256.
Full textAbstract:
碩士國立成功大學
化學工程學系
103
The aim of this study is to increase cell performances of cobalt-based gel-state dye-sensitized solar cells by using nano-fillers. Including: (1) TiO2 nano-particles (NPs), (2) Surface modified TiO2 NPs, (3) TiC NPs. In results, TiO2 fillers inhibit charge transfer on counter electrode, increase chances of electron leakage and lead to poorer efficiency (ƞ: 5.67%4.07%). The effects are studied and related to the electrocatalytic activity and the electrostatic attraction between TiO2 and [Co(bpy)3]2+/3+. In part 2, results show that recombination has been eased after applying modified TiO2 fillers, which have -NH2 or -NH3+ groups on particle surfaces. Thus, better performances (ƞ: 5.66%, 5.40%) are obtained but only approximate to the device without fillers (ƞ: 5.67%). In part 3, results show that TiC fillers facilitate charge transfer on counter electrode and conductivity of the electrolyte but also recombination. Therefore, an optimal efficiency 6.29% can be achieved at 3wt% TiC, which is comparable to liquid-state device 6.38%. In part 4, results show lower RPt after applying (Pt/ TiC) counter electrode, but RPt still increase after using TiO2-NH2 fillers, thence the overall efficiency is only 5.19%. At last in stability tests, liquid-state device can maintain only 65% of the initial efficiency in 50oC environment after 1000 hours, while the gel-state device with 3wt% TiC fillers can keep 92%. Thus, by the regulation from nano-fillers, efficiency of gel-state DSSC can reach to liquid-state DSSC as well and keep better thermal long-term stability.
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Liu, Chien-Hung, and 劉建宏. "Development of long-term stability of gel electrolyte dye-sensitized solar cells." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/21930271752339373020.
Full textAbstract:
碩士國立清華大學
工程與系統科學系
100
There are some bottlenecks for long-term stability of the liquid electrolyte based Dye-Sensitized Solar Cell (DSSC). Here we list two of the major problems leading poor long-term stability of devices : 1. The leakage of liquid electrolyte. 2. The damage of the device by ultraviolet irradiation. In this study, a new fabrication process for in-situ gel electrolyte DSSC is achieved in order to solve both the leakage problem of liquid electrolyte and the penetrating problem of gel electrolyte at the same time. To fabricate UV-protection in-situ gel electrolyte DSSC, the UV-protection electrolyte was prepared by mixing the UV absorber in certain percentage with liquid electrolyte(GBL-based) first. Polyvinyl butyral(PVB) was placed in the device before the injection of the UV-protection electrolyte, and dissoved in the liquid electrolyte to form the gel electrolyte spontaneously. The conversion efficiency recorded for the GBL-based electrolyte with 10wt% PVB and 5wt% UV absorber is 4.27%, which is about 85% of the liquid-type one, with values of Voc, Jsc, and FF of 0.73 (V), 11.73 (mA/cm2) and 0.5, respectively. Most important of all, the UV- protection in-situ gel electrolyte DSSC exhibits a well long-term stability, surprising 95% of its originl efficiency after 1000 working hours. With the high durability, resulting in the DSSC outdoor application in the near future. Key word: Dye-sensitized solar cell, gel-type electrolyte, long-term stability, UV absorber, Polyvinyl butyral(PVB)
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Hsueh-YiLin and 林學溢. "Butyronitrile-Based Electrolyte for Dye-Sensitized Solar Cells under low light intensity." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/s2nyjg.
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Jhong, Huei-Ru, and 鍾惠如. "The Study of Deep Eutectic Solvents and Their Applications to Nonvolatile Electrolytes for Dye-Sensitized Solar Cells." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/51248415393786684585.
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Guo, Tai-lin, and 郭泰麟. "Quasi-solid state electrolytes of Ionic liquid crystal apply in Dye-Sensitized Solar Cell." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/42760543618386215262.
Full textAbstract:
碩士國立中山大學
光電工程學系研究所
98
A novel ionic liquid crystal (ILC) system (C18IMCNBr) with a liquid crystal alignment used as an electrolyte for a dye-sensitized solar cell (DSSC) showed the higher short-circuit current density (Jsc) and the higher light-to-electricity conversion efficiency than the system using the non- alignment liquid crystalline ionic liquid (C18IMCNBr),due to the higher conductivity of liquid crystal alignment. The larger Jsc and efficiency value of liquid crystal alignment supported that the higher conductivity of liquid crystal alignment is attributed to the enhancement of the exchange reaction between iodide species. As a result of formation of the two-dimensional electron conductive pathways organized by the localized I3- and I- at liquid crystal alignment layers, the concentration of polyiodide species exemplified by Im- (m =5,7, ...) was higher in alignment C18IMCNBr. However, in the two-dimensional electron conductive pathways of C18IMCNBr, more collision frequencies between iodide species (I-,I3-, and Im-) could be achieved than that in the three-dimensional space of C18IMCNBr, which could lead to the promotion of the exchange reaction between iodide species, the contribution of a two-dimensional structure of the conductive pathway through the increase of collision frequency between iodide species was proposed.
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Lai, Yen-Chieh, and 賴彥榤. "Application of PVDF-HFP/mesoporous silica composite polymer electrolytes on dye-sensitized solar cell." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/5c6y6d.
Full textAbstract:
碩士中原大學
化學研究所
98
In this study, poly(vinylidenefluoride-co-hexafluoropropylene)(P(VDF-HFP)) were introduced into to liquid electrolyte to formed the gel electrolyte, and commercials silica (CS) and mesoporous silica (MS) powders were used, separately, as a filler to induced into the gel electrolyet. It is discussed that the properties of composite gel electrolyte and application of dye-sensitized solar cells. The morphologies and porosity of the silicas were characterized by SEM,TEM and BET measurements. The composite polymer electrolytes wrer investigated by morphologies, crystallinity, ionic conductivity, diffusion coefficient of tri-iodide and light-to-electrical-energy conversion efficiencies. It was found that presence of the CS were increased, the porosity of composite gel electrolytes were decreased, but P10MSx composite electrolytes were not changed obviously. And MS were disdrdered pore structure, electrolytes would penetrated into pores and increased ionic conductivity, diffusion coefficient of I3－. It exhibited an overall light-to-electrical-energy conversion efficiencies of 4.08 %, which is 37 % higher than the corresponding values of the DSSC fabricated with the electrolyte without MS additive, more then 9% higher than electrolyte under the same condition.
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Chou, Jia-Jen, and 周葭甄. "Influence of bis-benzimidazole derivative additive in electrolytes on dye-sensitized solar cell performance." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/229978.
Full textAbstract:
碩士國立臺北科技大學
化學工程研究所
99
Because of 4-tert-butylpyridine(4TBP) enhanced the photo-electron conversion efficiency successfully as an additive in electrolyte solution. Therefore, the interaction between nitrogen heterocycle as an additive and solar cell components cause influence on cell performance. In this thesis, we choose two bis-benzimidazole derivatives in different concentration and also mix with 4TBP to find out if they enhance or reduce efficiency of dye-sensitized solar cells. Using chronoamperometry and UV/Vis to find out the differences between electrolytes. Using I-V curve, IPCE and EIS to define photo-electron conversion efficiency, incident photon-to-electron conversion efficiency and impendence inside cells to prove additives do make influence on dye-sensitized solar cells.
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TsengShan, Chih-Mei, and 曾山智美. "Preparation of Cobalt-Based Quasi-Solid State Electrolytes for Dye-Sensitized Solar Cell Applications." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/m7vr5e.
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