Journal articles: 'Peak Plasmon Absorption'

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Solidum, Ruelson S., Arnold C. Alguno, and Rey Capangpangan. "Controlling the Surface Plasmon Absorption of Silver Nanoparticles via Green Synthesis Using Pennisetum purpureum Leaf Extract." Key Engineering Materials 772 (July 2018): 73–77. http://dx.doi.org/10.4028/www.scientific.net/kem.772.73.

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We report on the green synthesis of silver nanoparticles utilizing theP.purpureumleaf extract. Controlling the surface plasmon absorption of silver nanoparticles was achieved by regulating the amount of extract concentration and the molarity of silver nitrate solution. The surface plasmon absorption peak is found at around 430nm. The surface plasmon absorption peak have shifted to lower wavelength as the amount of extract is increased, while plasmon absorption peak shifts on a higher wavelength as the concentration of silver nitrate is increased before it stabilized at 430nm. This can be explained in terms of the available nucleation sites promoted by the plant extract as well as the available silver ions present in silver nitrate solution.

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Hashemi, Mahdieh, Narges Ansari, and Mahsa Vazayefi. "Absorption peak wavelength and bandwidth control in MoS₂-based absorbers on the basis of SPPs and LSPs excitation." Optical Materials Express 13, no. 4 (2023): 850. http://dx.doi.org/10.1364/ome.481687.

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The nanometer-sized absorber that we introduced in this paper consists of a monolayer of atomically thin MoS2 on a silica substrate covered by inclined gold gratings. By selecting the period of the gold grating of the order of the incident light wavelength, both surface plasmon polaritons (SPPs) and localized surface plasmons (LSPs) can be excited in the structure at the visible spectrum. By selecting different values of the gold ribbon’s widths, we show that the excited modes can be adjusted to SPPs, LSPs, or SPPs and LSPs together. With the excitation of SPPs, the narrowband absorption peak wavelength, and with the excitation of LSPs, the FWHM of the absorption peak can be adjusted by the ribbon’s geometry parameters. In the case of simultaneous excitation of SPPs and LSPs, by increasing the ribbons’ inclination, the LSP peaks will redshift, while the SPP peaks blueshift, which leads to wider absorption peaks. The effect of increasing the ribbons’ height is opposite to that of the ribbons’ inclination, which is accompanied by the SPP peak red shift and LSP peak blue shift. This way, the more the height of the ribbons, the less the absorption peak bandwidth is. This paper’s results are a promising guide for designing plasmonic absorbers with desired bandwidths and peak wavelengths, which are widely demanded in designing photovoltaics and photonic sensors.

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Koshelev, Ilya R., Asiya I. Mukhammad, and Peter I. Gaiduk. "Modeling of plasmon resonance in periodic multilayer structures based on chromium with a surface island layer." Journal of the Belarusian State University. Physics, no. 1 (February 9, 2021): 26–32. http://dx.doi.org/10.33581/2520-2243-2021-1-26-32.

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The optical properties of Cr/Si/Cr and Cr/CrSi2 /Cr structures with periodically located chromium islands are modeled using the finite-difference time domain method. These structures are characterized by the phenomenon of plasmon resonance. The dependences of the intensity and position of the plasmon absorption peak on the thickness and radius of the islands are determined. It was observed that when the island thickness increases to 120 nm, the intensity of the absorption peak increases to 69 % for the Cr/Si/Cr structure and to 55 % for the Cr/CrSi2 /Cr structure. It was found that the peak of plasmon absorption in the spectrum of the Cr/Si/Cr structure is at a shorter wavelength (8.4 µm for Cr/Si/Cr, 11.1 µm for Cr/CrSi2/Cr), and also has a higher intensity (the share of absorbed radiation is 14 % higher compared to the peak of plasmon absorption in the spectrum of the Cr/CrSi2 /Cr structure). The obtained dependences indicate that the Cr/Si/Cr and Cr/CrSi2 /Cr structures can be used as IR detectors.

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Silva, Jaime, Bruce F. Milne, and Fernando Nogueira. "On the Single Wall Carbon Nanotube Surface Plasmon Stability." EPJ Web of Conferences 233 (2020): 05009. http://dx.doi.org/10.1051/epjconf/202023305009.

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The physics of surface plasmons has a long tradition in condensed matter theory but as the dimension of the systems reaches the nano scale, new effects appear. In this work, by calculating the absorption spectra of a single wall carbon nanotube, using time dependent density functional theory, the effect of adding/removing electrons on the surface plasmon energy is studied. It is shown that removing electrons from the single wall carbon nanotube does not affect the surface plasmon energy peak. In contrast, adding electrons to the single wall carbon nanotube will redshift the plasmonic peak energy, an effect that is explained by an increase of the electron effective mass.

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CHEN, FENGXIANG, WENYING XU, and LISHENG WANG. "RESEARCH ON OPTICAL ABSORPTION CHARACTERISTICS OF Ag NANOPARTICLES." Modern Physics Letters B 27, no. 11 (2013): 1350079. http://dx.doi.org/10.1142/s0217984913500796.

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In this work, Ag nanoparticles were deposited on quartz glass substrates by magnetron sputtering method, and the morphology was characterized by SEM. Ag nanoparticle surface plasmon resonance characteristics were observed by transmittance measurement. The experimental results demonstrated an increase in particle size that was correlated to an increase in sputtering time and a plasmon resonance absorption peak redshift. This phenomenon was partially explained by Mie scattering model. The differences between our theoretical analysis and experimental results show that both the shape of and the spacing between nanoparticles are key parameters affecting plasmon resonance peak location.

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Nika, Denis, Evghenii Pokatilov, Vladimir Fomin, Josef Devreese, and Jacques Tempere. "Resonant Terahertz Light Absorption by Virtue of Tunable Hybrid Interface Phonon–Plasmon Modes in Semiconductor Nanoshells." Applied Sciences 9, no. 7 (2019): 1442. http://dx.doi.org/10.3390/app9071442.

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Metallic nanoshells have proven to be particularly versatile, with applications in biomedical imaging and surface-enhanced Raman spectroscopy. Here, we theoretically demonstrate that hybrid phonon-plasmon modes in semiconductor nanoshells offer similar advantages in the terahertz regime. We show that, depending on tm,n,nhe doping of the semiconductor shells, terahertz light absorption in these nanostructures can be resonantly enhanced due to the strong coupling between interface plasmons and phonons. A threefold to fourfold increase in the absorption peak intensity was achieved at specific values of electron concentration. Doping, as well as adapting the nanoshell radius, allowed for fine-tuning of the absorption peak frequencies.

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Bogdanov, P. A., L. A. Sokura, A. V. Kremleva, and V. V. Vitkin. "Sol-Gel Synthesis of Uniform Arrays of Ag and Au Nanoparticles." Reviews on Advanced Materials and Technologies 5, no. 1 (2023): 39–44. http://dx.doi.org/10.17586/2687-0568-2023-5-1-39-44.

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The obtaining of uniform arrays of silver and gold nanoparticles with a surface density up to 3.3∙109 cm–2 on the zinc oxide buffer layers by sol-gel method is described. The variations of the solution composition and synthesis mode, layers coating and subsequent heat treatment were carried out. The absorption spectra of the obtained samples had a peak near 400–570 nm corresponding to the plasmon resonance in the Ag and Au nanoparticles. Wavelength and shape of Ag and Au nanoparticles plasmon peak varied depending on the synthesis mode: the use of ZnO buffer layers leads to an increase in the intensity of the nanoparticles plasmon peak, the annealing leads to a gradual decrease and broadening of the absorption peak of Ag and mixed Ag and Au nanoparticles arrays, but does not affect the peak of Au nanoparticles.

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Alireza, Heidari. "Biomedical and Biochemical Approaches and Strategies for Targeting and Delivery of Cadmium Oxide (CdO) Nanoparticles Aggregation Linked to DNA/RNA by Aryl Mercaptanes with Various Chain Length." Biomedicine and Chemical Sciences 1, no. 4 (2022): 215–24. https://doi.org/10.48112/bcs.v1i4.149.

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CdO nanoparticles show a strong peak of Plasmon absorption in ultraviolet-visible zone. A strong interaction exists between the surface of CdO nanoparticles and aryl mercaptan compounds. Aryl mercaptan compounds cause to aggregation of CdO nanoparticles linked to DNA/RNA and hence, lead to widening of peak Plasmon of CdO nanoparticles surface at 550 (nm) and emerging a new peak at higher wavelength. In the current project, this optical characteristic of CdO nanoparticles is used to time investigate of interaction between different aryl mercaptanes and CdO nanoparticles. The results were shown that aryl mercaptan compounds with shorter chain length interact faster with CdO nanoparticles. Therefore, a simple and fast method for identification of aryl mercaptanes with various chain length using red shift in surficial Plasmon absorption is presented.

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Ye, Fenghua, Huan Ye, and Xiaozhi Wang. "Design and experimental verification of a perfect dual-band optical metamaterial absorber." Modern Physics Letters B 31, no. 08 (2017): 1750047. http://dx.doi.org/10.1142/s0217984917500476.

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A perfect dual-band optical absorber is designed and measured. A low absorption peak (P1) and two high absorption peaks (P2 and P3) are obtained. The P1 peak is excited by the resonance of internal surface plasmon (ISP) mode. The P2 peak is resulted by the coupling of local surface plasma (LSP) modes and the resonance of ISP mode. The P3 peak is excited by the resonance of ISP mode. The damping constant of the gold film is optimization calculated in simulations. Measured results indicate that high absorption performed is obtained with different dielectric layers. The measured metamaterial absorber displays high absorption performed at TM and TE configurations. Moreover, the proposed metamaterial absorber is sensitivity on the change of the refractive index of the environmental media.

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Heidari, Alireza. "Biomedical and Biochemical Approaches and Strategies for Targeting and Delivery of Cadmium Oxide (CdO) Nanoparticles Aggregation Linked to DNA/RNA by Aryl Mercaptanes with Various Chain Length." Biomedicine and Chemical Sciences 1, no. 4 (2022): 215–24. http://dx.doi.org/10.48112/bcs.v1i4.149.

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CdO nanoparticles show a strong peak of Plasmon absorption in ultraviolet-visible zone. A strong interaction exists between the surface of CdO nanoparticles and aryl mercaptan compounds. Aryl mercaptan compounds cause to aggregation of CdO nanoparticles linked to DNA/RNA and hence, lead to widening of peak Plasmon of CdO nanoparticles surface at 550 (nm) and emerging a new peak at higher wavelength. In the current project, this optical characteristic of CdO nanoparticles is used to time investigate of interaction between different aryl mercaptanes and CdO nanoparticles. The results were shown that aryl mercaptan compounds with shorter chain length interact faster with CdO nanoparticles. Therefore, a simple and fast method for identification of aryl mercaptanes with various chain length using red shift in surficial Plasmon absorption is presented.

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Heidari, Alireza. "A New Viewpoint and Outlook on Aryl Mercaptans as Strong Nucleophiles with Various Chain Length Linked to DNA/RNA and Cadmium Oxide (CdO) Nanoparticles Sandwiched Complex." Asian Journal of Engineering and Applied Technology 10, no. 2 (2021): 34–38. http://dx.doi.org/10.51983/ajeat-2021.10.2.3073.

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CdO nanoparticles show a strong peak of Plasmon absorption in ultraviolet–visible zone. A strong interaction exists between the surface of CdO nanoparticles and aryl mercaptan compounds. Aryl mercaptan compounds cause to aggregation of CdO nanoparticles linked to DNA/RNA and hence, lead to widening of peak Plasmon of CdO nanoparticles surface at 550 (nm) and emerging a new peak at higher wavelength. In the current project, this optical characteristic of CdO nanoparticles is used to time investigate of interaction between different aryl mercaptanes and CdO nanoparticles. The results were shown that aryl mercaptan compounds with shorter chain length interact faster with CdO nanoparticles. Therefore, a simple and fast method for identification of aryl mercaptanes with various chain length using red shift in surficial Plasmon absorption is presented.

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Alireza Heidari. "Spectrophotometr ic Study of Aryl Mercaptanes with Various Chain Length Linked to DNA/RNA and Cadmium Oxide (CdO) Nanoparticles Sandwiched Complex." Journal of Kufa for Chemical Sciences 2, no. 9 (2023): 475–500. http://dx.doi.org/10.36329/jkcm/2022/v2.i9.13316.

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CdO nanoparticles show a strong peak of Plasmon absorption in ultraviolet–visible zone. A strong interaction exists between the surface of CdO nanoparticles and aryl mercaptan compounds. Aryl mercaptan compounds cause to aggregation of CdO nanoparticles linked to DNA/RNA and hence, lead to widening of peak Plasmon of CdO nanoparticles surface at 550 (nm) and emerging a new peak at higher wavelength. In the current project, this optical characteristic of CdO nanoparticles is used to time investigate of interaction between different aryl mercaptanes and CdO nanoparticles. The results were shown that aryl mercaptan compounds with shorter chain length interact faster with CdO nanoparticles. Therefore, a simple and fast method for identification of aryl mercaptanes with various chain length using red shift in surficial Plasmon absorption is presented.

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Osaka, Yoshiki, Nobuhiko Yokoshi, and Hajime Ishihara. "Radiation-Induced Correlation between Molecules Nearby Metallic Antenna Array." International Journal of Antennas and Propagation 2015 (2015): 1–6. http://dx.doi.org/10.1155/2015/747580.

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We theoretically investigate optical absorption of molecules embedded nearby metallic antennas by using discrete dipole approximation method. It is found that the spectral peak of the absorption is shifted due to the radiation-induced correlation between the molecules. The most distinguishing feature of our work is to show that the shift is largely enhanced even when the individual molecules couple with localized surface plasmons near the different antennas. Specifically, we first consider the case that two sets of dimeric gold blocks with a spacing of a few nanometers are arranged and reveal that the intensity and spectral peak of the optical absorption strongly depend on the position of the molecules. In addition, when the dimeric blocks and the molecules are periodically arranged, the peak shift is found to increase up to ~1.2 meV (300 GHz). Because the radiation-induced correlation is essential for collective photon emission, our result implies the possibility of plasmon-assisted superfluorescence in designed antenna-molecule complex systems.

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Vodnik, Vesna V., Dušan K. Božanić, Nataša Bibić, Zoran V. Šaponjić, and Jovan M. Nedeljković. "Optical Properties of Shaped Silver Nanoparticles." Journal of Nanoscience and Nanotechnology 8, no. 7 (2008): 3511–15. http://dx.doi.org/10.1166/jnn.2008.144.

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The influence of shape and dielectric property of surrounding media on surface plasmon absorption band of silver nanoparticles was studied. Spherical silver nanoparticles (d = 5.6 nm) synthesized in water using NaBH4 as a reducing agent are transferred in non-polar solvent (chloroform) with phase-transfer reagent oleylamine. The absorption spectrum of oleylamine-capped silver nanoparticles dispersed in chloroform shows a strong surface plasmon resonance band that is 19 nm red-shifted compared to unmodified particles in water. The values for peak position and corresponding half widths are compared with theoretical calculations based on Mie theory. Prismatic and plate-like silver nanoparticles were synthesized in water using trisodium citrate as a reducing agent and cetyltrimethylammonium bromide as stabilizer. Due to structural anisotropy of prismatic and plate-like silver nanoparticles three surface plasmon resonance bands were observed in absorption spectrum. Nanocomposites consisting of non-spherical silver nanoparticles and polyvinyl alcohol exhibit different optical properties compared to water colloid. Instead of three surface plasmon bands, nanocomposite film has only one peak at 460 nm. Reason for appearance of single surface plasmon resonance band in nanocomposite film was discussed according to Maxwell-Garnet theory.

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Sun, Jin, Zongling Ding, Yuanqin Yu, and Chuanmei Xie. "A Theoretical Investigation about Photoswitching of Azobenzene Adsorbed on Ag Nanoparticles." Crystals 12, no. 2 (2022): 248. http://dx.doi.org/10.3390/cryst12020248.

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The optical properties of hybrid systems composed of silver nanoparticles (NPs) and azobenzene molecules were systematically investigated by combining the real-time time-dependent density functional theory (RT-TDDFT) approach with the classical electrodynamics finite difference time domain (FDTD) technique for the solution of Maxwell’s equations. In order to reflect the chemical interaction between azobenzene and metal more exactly, except for adsorbed molecules, a Ag cluster separated from NP was also dealt, using RT-TDDFT. We studied the different factors affecting the surface-enhanced absorption spectra. It was found that the electric field amplified by plasmon resonance of Ag NPs can have an overall enhancement to the molecular light absorption throughout the whole energy range. The resonance between the electron and the plasmon excitation results in a larger percentage of enhancement in the absorption spectrum the closer the resonance peak is. The enhancement ratio of the resonance peak is the largest. The plasmon–exciton coupling and the optical properties of different isolate isomers influence the line shape of the absorption spectra. The dipole interaction and electronic transfer between azobenzene molecules and Ag NPs also change the shape of spectroscopy from the absorption enhancement ratio and the location of the peak. Physical and chemical factors lead to photoswitching in these hybrid systems together.

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Heidari, Alireza. "Interaction between Cadmium Oxide (CdO) Nanoparticles Aggregation Linked to DNA/RNA and Aryl Mercaptanes With Various Chain Length." Academic Journal of Chemistry, no. 72 (April 28, 2022): 23–29. http://dx.doi.org/10.32861/ajc.72.23.29.

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CdO nanoparticles show a strong peak of Plasmon absorption in ultraviolet–visible zone. A strong interaction exists between the surface of CdO nanoparticles and aryl mercaptan compounds. Aryl mercaptan compounds cause aggregation of CdO nanoparticles linked to DNA/RNA and hence, lead to widening of peak Plasmon of CdO nanoparticles surface at 550 (nm) and emerging a new peak at a higher wavelength. In the current project, this optical characteristic of CdO nanoparticles is used to time investigate of interaction between different aryl mercaptanes and CdO nanoparticles. The results were shown that aryl mercaptan compounds with shorter chain length interact faster with CdO nanoparticles. Therefore, a simple and fast method for identification of aryl mercaptanes with various chain length using red shift in surficial Plasmon absorption is presented. Schematic of Cadmium Oxide (CdO) Nanoparticles Aggregation Linked to DNA/RNA by Aryl Mercaptanes with Various Chain Length.

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Guo, Zi-Zheng. "Effect of dielectric environment on plasmonic resonance absorption of graphene nanoribbon arrays." International Journal of Modern Physics B 32, no. 26 (2018): 1850284. http://dx.doi.org/10.1142/s0217979218502843.

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The plasmonic resonance absorption properties of a periodic graphene nanoribbon array are studied in this paper. We discuss the effect of the asymmetricity of the dielectric environment on the plasmonic resonance of the graphene nanoribbon array in order to know which combination of the two dielectric materials surrounding the graphene is most advantageous. The results show that, regardless of the graphene in symmetric and asymmetrical environments, the absorption peak of plasmon resonance shifts to longer wavelengths (shifts red) with the increase of the changing permittivity (permittivities) on one or both sides. This absorption characteristic of the graphene periodic array to external electromagnetic waves originates from the wavelength dependence of the intrinsic graphene plasmons on the environmental medium.

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Pyatnov, Maxim V., Rashid G. Bikbaev, Ivan V. Timofeev, Ilya I. Ryzhkov, Stepan Ya Vetrov, and Vasily F. Shabanov. "Tamm Plasmons in TiO2 Nanotube Photonic Crystals." Photonics 10, no. 1 (2023): 64. http://dx.doi.org/10.3390/photonics10010064.

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The anodic TiO2 photonic crystals evoke great interest for application as photocatalytic media due to high absorption of light resuling from their specific structure. In this work, the optical properties of the photonic crystal based on a bamboo-type TiO2 nanotube with a metallic coating are analyzed theoretically by the finite-difference time-domain method. The occurrence of Tamm plasmons that appears as a peak in the absorption spectrum is predicted. A Tamm plasmon polariton is a localized state of light excited at the boundary of two highly reflective media, a metal and a Bragg reflector. The integral absorption of the gold-, titanium-, and titanium nitride-coated photonic crystals in the wavelength range of 450–600 nm is calculated. It is established that the titanium nitride-coated structure exhibits the maximum integral absorption.

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Filatov, D. O., I. N. Antonov, D. Yu Sinutkin, et al. "Plasmon resonance induced photoconductivity in the yttria stabilized zirconia films with embedded Au nanoclusters." Физика и техника полупроводников 52, no. 4 (2018): 470. http://dx.doi.org/10.21883/ftp.2018.04.45819.08.

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AbstractWe report on the investigation of the photoconductivity (PC) in the yttria stabilized zirconia (YSZ) films with embedded Au nanoclusters (NCs). A peak in the PC spectrum corresponding to the plasmon optical absorption resonance in the Au NCs was observed. The temperature dependence of PC near 300 K obeyed Mott law. In this case, the PC was attributed to the heating of the YSZ matrix due to the plasmon optical absorption in the Au NCs (bolometric effect). Near 77 K, the PC did not depend on temperature and was attributed to plasmon-assisted electron transport between the NCs via the vacancy α-band in YSZ.

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Yin, Zhe, Jianhui Song, Yang Yu, Hongwei Gao, Jun Liu, and Yawei Zhao. "Tunable narrowband metamaterial perfect absorber with single absorption peak." Modern Physics Letters B 34, no. 28 (2020): 2050303. http://dx.doi.org/10.1142/s0217984920503030.

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A tunable narrowband metamaterial perfect absorber (NMPA) with single absorption peak at both normal incidence and oblique incidence is proposed. The spectral responses of the designed NMPA are calculated using finite-difference time-domain (FDTD) method. By using an Ag guided-mode resonance grating layer with great fill factor, the designed NMPA exhibits single resonance peak, which is converted to heat due to the strong surface plasmon resonance around the Ag grating and the Ag substrate. An NMPA sample is fabricated and the spectral responses are measured to verify the theoretical results. The experimental results are consistent with the theoretical ones.

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Zhao, Wenhan, Junqiao Wang, Ran Li, and Bin Zhang. "Ultranarrow dual-band metamaterial perfect absorber and its sensing application." Journal of Optics 24, no. 3 (2022): 035103. http://dx.doi.org/10.1088/2040-8986/ac4aba.

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Abstract In this paper, a dual-band metamaterial absorber (MMA) with wide-angle and high absorptivity is proposed. The MMA consists of two silver layers separated by a dielectric layer. Its top resonant element is constituted by two concentric ring resonators connected with four strips. Based on electromagnetic field simulation, the proposed MMA has two narrow absorption peaks with an absorption rate of 99.9% at 711 nm and 99.8% at 830 nm, and the corresponding line width of the two absorption peaks are only 9.7 and 9.8 nm. The dual-band MMA shows high absorptivity under wide incident angles. The simulated field pattern shows that dual-band perfect absorption is the combined result of the interaction of two concentric ring resonators and unit cell coupling. In addition, the hexapole plasmon mode can be observed at the outer ring at one absorption peak. The narrow plasmon resonance has a potential application in optical sensing, and can be used to measure the concentration of aqueous glucose with two frequency channels. The proposed MMA with high absorptivity is simple to manufacture, and has other potential applications, such as narrow-band filters, energy storage device, and so on.

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Wang, Ying Lian, Jun Yao Ye, and Ren Fen Zeng. "Preparation and Properties of Ag Nanofilms for Organic Solar Cells." Applied Mechanics and Materials 540 (April 2014): 21–24. http://dx.doi.org/10.4028/www.scientific.net/amm.540.21.

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nanoAg island thin films with different thickness have been prepared by vacuum vapor deposition method on ITO substrates for organic solar cells. UV-Vis absorption spectrum and surface morphology have been studied by UV-Vis scanning spectrophotometer and SEM. The influence of different thickness nanoAg has also been discussed. The results show that, when the nanoAg thickness is 3.0 nm, the surface plasmon response is most obvious, the resonance absorption peak appears red-shift, the surface plasmon response could enhance optical absorption, photocurrent, fill factor and power conversion efficiency obviously. The research results provide theoretical guidance to optimize the design and increase the performance of solar cells.

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XIAO, GUI-NA, SHI-QING MAN, HUA-LI ZHANG, and YAN-XIAO FENG. "PREPARATION AND SURFACE PLASMON RESONANCE OF COPPER NANOCAP ARRAYS." Modern Physics Letters B 25, no. 08 (2011): 599–604. http://dx.doi.org/10.1142/s0217984911025791.

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Copper nanocap arrays, consisting of a SiO 2 core with a Cu cap, were prepared by chemical synthesis combined with physical evaporation technique. The obtained samples were characterized by scanning electron microscopy, atomic force microscopy, X-ray diffraction, and ultraviolet-visible-near-infrared spectrophotometer. The copper nanocap arrays were found to exhibit tunable surface plasmon resonance (SPR) absorption peaks that were red-shifted as the ratio of the SiO 2 core diameter to the Cu cap thickness increased. While the cap thickness varied between 20 nm and 50 nm, the SPR peak shifted from 1650 nm to 1230 nm. While the core diameter varied between 140 nm and 400 nm, the longitudinal SPR peak shifted from 1243 nm to 1830 nm.

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Yeneayehu, Kinde, Teshome Senbeta, and Belayneh Mesfin. "The effect of surface plasmonic resonances on magneto-plasmonic spherical core-shell nanocomposites." SINET: Ethiopian Journal of Science 45, no. 2 (2022): 132–42. http://dx.doi.org/10.4314/sinet.v45i2.2.

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In this study, the effect of plasmon resonance on magneto-plasmonic spherical core-shell nanocomposite enclosed in a dielectric host medium is theoretically investigated by applying electrostatic approximation (esa) and Maxwell-Garnet effective medium theories to obtain magneto-optical parameters such as; effective electric permittivity and magnetic permeability as well as the corresponding extinction cross-sections. Likewise, for a fixed size of QDs (of radius nm) numerical analysis was performed to determine the plasmonic resonance effect by varying the parameters such as the metal fraction (β) and the dielectrics (εh) of the host medium on the magneto-plasmonic nanostructures (nss). The results depict that graphs of absorption, scattering, and extinction cross-sections as a function of wavelength have two positions of resonance peaks. The first set of peaks are in the ultraviolet (uv) and the second located in visible regions. These peaks originated from the strong coupling between a regular periodic vibrations of surface plasmons of silver (Ag) with the excitonic state of the dielectric/semiconductor at the internal ( ) and external (Ag/host) interfaces. As β increases, the absorption and scattering cross-sections are blue-shifted in the first peak and red shifted the second set of peaks. Similarly, as εh increases or as β decreases, the sets of resonance peaks for extinction cross-section gets enhanced; while keeping one of these parametric quantities fixed at once. The resulting surface plasmon resonance effect might be utilized in a variety of applications that combines both the plasmonic and magnetic core-shell nanostructures ranging from UV to Visible spectral regions.

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Borisov, V. I., A. A. Lizunova, D. Malo, E. I. Kameneva, A. A. Ramanenka, and V. V. Ivanov. "Synthesis of gold nanoparticles by the spark discharge method for visible plasmonics." Journal of Physics: Conference Series 2086, no. 1 (2021): 012002. http://dx.doi.org/10.1088/1742-6596/2086/1/012002.

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Abstract This work demonstrates synthesis of metal Au nanoparticles with a plasmon resonance in the visible optical region by the spark discharge method in atmosphere of argon of purity 6.0. With raising of sintering temperature from 25 to 950 °C, the morphology of synthesized Au nanoparticles changed from agglomerates to individual particles with decreasing the median size from 270 to 90 nm according to aerosol spectrometer. While by transmission electron microscopy primary nanoparticles with a gold crystalline structure with sizes in range from 5 to 120 nm were observed. Synthesized nanoparticles ensembles had broad absorption peaks with maximum in the visible optical region with peak positions approximately at 490 nm. High temperature sintered particles had a spherical shape and an additional absorption peak at approximately 640 nm.

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Chen, Yan Ming, and Jing Wang. "Synthesis of Gold Nanoparticles Stabilized by 3-(Aminopropyl)Triethoxysilane through (N, N-Dimethylformamide) Reduction." Applied Mechanics and Materials 184-185 (June 2012): 1298–301. http://dx.doi.org/10.4028/www.scientific.net/amm.184-185.1298.

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gold nanoparticles were synthesized in DMF (N, N-dimethylformamide) solution by using 3-(aminopropyl)triethoxysilane as stabilizer through wet chemical route. A characteristic surface plasmon band can be observed for the obtained gold nanoparticles from UV-vis absorption spectra, which indicate that KH-550 can serve as stabilizing agent for the formation of gold nanoparticles. The influence of reaction temperature, reaction time and precursor concentrations on the formation of gold nanoparticles is investigated through UV-vis absorption spectra. The results show that surface plasmon absorption peak could be red-shifted when reaction temperature, reaction time and precursor concentrations increase. Transmission electron microscopy (TEM) results show that the obtained gold nanoparticles with spherical morphology have a narrow size distribution.

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Minun, Caessandra Addine, Nur Zehan An’Nisa, Marlia Morsin, et al. "Investigation on the Effect of Centrifugation Speed on the Shape Separation of Gold Nanorods." International Journal of Engineering & Technology 7, no. 4.30 (2018): 330. http://dx.doi.org/10.14419/ijet.v7i4.30.22302.

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High-quality gold nanorods (AuNRs) with a uniform aspect ratio and sizes are crucial for applications in biomedical or sensor industry. AuNRs is implementing Localized Surface Plasmon Resonance (LSPR) as sensing method which is highly dependent on the size, separation of nanoparticles, aspect ratio and the shape of the nanoparticles. Thus, in this process, the shape, surface density and aspect ratio of AuNRs were investigated to be used further as LSPR sensing material. The AuNRs was prepared using Seed Mediated Growth Method (SMGM) and the growth solution of the AuNRs was centrifuged with the speed ranging from 2500 rpm to 5000 rpm to separate the particles shaper prior to deposition as thin film. The XRD result shows the peak at 2θ = 38º which shows the (111) crystal orientation of the AuNRs. There are also two distinct peaks formed at the absorption spectra graph obtained from the UV-Vis result which associated with transverse plasmon peak (t-LSPR) and longitudinal plasmon peak (l-LSPR). The t-LSPR peak is significantly smaller than the l-LSPR and located in the wavelength ranges from 500 nm to 560 nm whereas the l-LSPR of the AuNRs shows a stronger and a higher peak which is located in the wavelength ranges from 700 nm to 780 nm. The morphological analysis using FESEM shows that the higher centrifugation speed separates the AuNRs with higher aspect ratio and higher surface density.

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Tuo, Yong Feng, Yu Ping Wu, Min Huang, et al. "The Surface Plasmon Resonance Absorption of Indium Tin Oxide Nanoparticles and its Control." Advanced Materials Research 1118 (July 2015): 160–65. http://dx.doi.org/10.4028/www.scientific.net/amr.1118.160.

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Indium tin oxide (ITO) nanoparticles (NPs) were prepared by a coprecipitation process from a mixed solution consisting of indium chloride and tin chloride. The surface plasmon resonance (SPR) absorption was studied under different calcinate atmospheres. The characteristics of the optical properties, especially the absorption of near-infrared (NIR) region was recorded by the UV-Vis-NIR absorption spectroscopy. The results show that the SPR absorption peak appears at 2500 nm under an oxidizing atmosphere (air) or at 1300 nm under a reducing atmosphere (a gas mixture of Ar and 5 vol% H2) when calcinated under a single atmosphere. There is no change in the plasmon frequency with the variance of calcinate temperatures and therefore no change in the free carrier concentration. However, when calcinated first at 600 °C under an oxidizing atmosphere and then reheated under a reducing atmosphere at different temperature, the SPR absorption peaks of the ITO NPs are at the range of from 1200 nm to 1430 nm, undergoing a blue shift as the reducing process temperature increases. The SPR absorption of the prepared ITO NPs is easily controlled by calcinate temperature under a process of calcination first under an oxidizing atmosphere and followed by under a reducing atmosphere.

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Irimpan, Litty, V. P. N. Nampoori, and P. Radhakrishnan. "Enhanced luminescence and nonlinear optical properties of nanocomposites of ZnO–Cu." Journal of Materials Research 23, no. 11 (2008): 2836–45. http://dx.doi.org/10.1557/jmr.2008.0364.

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In this article, we present the spectral and nonlinear optical properties of ZnO–Cu nanocomposites prepared by colloidal chemical synthesis. The emission consisted of two peaks. The 385-nm ultraviolet (UV) peak is attributed to ZnO and the 550-nm visible peak is attributed to Cu nanocolloids. Obvious enhancement of UV and visible emission of the samples is observed and the strongest UV emission of a typical ZnO–Cu nanocomposite is over three times stronger than that of pure ZnO. Cu acts as a sensitizer and the enhancement of UV emission are caused by excitons formed at the interface between Cu and ZnO. As the volume fraction of Cu increases beyond a particular value, the intensity of the UV peak decreases while the intensity of the visible peak increases, and the strongest visible emission of a typical ZnO–Cu nanocomposite is over ten times stronger than that of pure Cu. The emission mechanism is discussed. Nonlinear optical response of these samples is studied using nanosecond laser pulses from a tunable laser in the wavelength range of 450–650 nm, which includes the surface plasmon absorption (SPA) band. The nonlinear response is wavelength dependent and switching from reverse saturable absorption (RSA) to saturable absorption (SA) has been observed for Cu nanocolloids as the excitation wavelength changes from the low absorption window region to higher absorption regime near the SPA band. However, ZnO colloids and ZnO–Cu nanocomposites exhibit induced absorption at this wavelength. Such a changeover in the sign of the nonlinearity of ZnO–Cu nanocomposites, with respect to Cu nanocolloids, is related to the interplay of plasmon band bleach and optical limiting mechanisms. The SA again changes back to RSA when we move over to the infrared region. The ZnO–Cu nanocomposites show self-defocusing nonlinearity and good nonlinear absorption behavior. The nonlinear refractive index and the nonlinear absorption increases with increasing Cu volume fraction at 532 nm. The observed nonlinear absorption is explained through two-photon absorption followed by weak free-carrier absorption and interband absorption mechanisms. This study is important in identifying the spectral range and composition over which the nonlinear material acts as a RSA-based optical limiter. ZnO–Cu is a potential nanocomposite material for the light emission and for the development of nonlinear optical devices with a relatively small limiting threshold.

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Fernandes, Joshua, and Sangmo Kang. "Numerical Study on the Surface Plasmon Resonance Tunability of Spherical and Non-Spherical Core-Shell Dimer Nanostructures." Nanomaterials 11, no. 7 (2021): 1728. http://dx.doi.org/10.3390/nano11071728.

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The near-field enhancement and localized surface plasmon resonance (LSPR) on the core-shell noble metal nanostructure surfaces are widely studied for various biomedical applications. However, the study of the optical properties of new plasmonic non-spherical nanostructures is less explored. This numerical study quantifies the optical properties of spherical and non-spherical (prolate and oblate) dimer nanostructures by introducing finite element modelling in COMSOL Multiphysics. The surface plasmon resonance peaks of gold nanostructures should be understood and controlled for use in biological applications such as photothermal therapy and drug delivery. In this study, we find that non-spherical prolate and oblate gold dimers give excellent tunability in a wide range of biological windows. The electromagnetic field enhancement and surface plasmon resonance peak can be tuned by varying the aspect ratio of non-spherical nanostructures, the refractive index of the surrounding medium, shell thickness, and the distance of separation between nanostructures. The absorption spectra exhibit considerably greater dependency on the aspect ratio and refractive index than the shell thickness and separation distance. These results may be essential for applying the spherical and non-spherical nanostructures to various absorption-based applications.

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Mandke, Mohanrao V., and Habib M. Pathan. "Multipole Surface Plasmon Resonance in Electrodeposited Gold Nanoparticles." International Journal of Nanoscience 13, no. 02 (2014): 1450014. http://dx.doi.org/10.1142/s0219581x14500148.

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Electrodeposition is a convenient, economical and template-free tool to create the gold nanostructures. A two-electrode electrochemical process is used for the deposition process. In this method by controlling the deposition time and electrode potential, nearly spherical and rod-like gold nanostructures were synthesized through the reduction of Chlorauric acid with citric acid as a complexing agent. Spherical gold nanostructures of different size around 2 nm to 30 nm and rod-like nanostructures with an aspect ratio 0.5 were grown directly on fluorine-doped tin oxide (FTO)-coated glass substrate. The growth mechanism of gold nanostructures is explained with the help of oriented attachment process. The contact angle measurement showed the hydrophilic nature of gold nanostructures using water with contact angle of about 56°. The optical properties showed a dipole, quadrupole and an octupole plasmon resonance mode at around 625 nm, 530 nm and 422 nm respectively. The dipole resonance peak extends further to give a broad absorption band in the near infrared region of electromagnetic waves. The refractive index sensitivity of gold nanoparticles in various solvents was investigated by calculating the red shift of surface plasmon resonance (SPR) peaks. The quadrupole plasmon resonance mode showed maximum SPR sensitivity as compared to dipole and octupole plasmon resonance mode. The controlled formation of gold nanoparticles with variation of SPR over wide range of visible region supports the potential applications in biosensors, nanoelectronics and plasmon enhanced light absorption in photovoltaics, etc.

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Yokoyama, Eisuke, Hironobu Sakata, and Moriaki Wakaki. "Sol-gel synthesis and characterization of Ag nanoparticles in ZrO2 thin films." Journal of Materials Research 24, no. 8 (2009): 2541–46. http://dx.doi.org/10.1557/jmr.2009.0314.

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ZrO2 thin films containing silver nanoparticles were prepared using the sol-gel method with Ag to Zr molar ratios [Ag]/[Zr] = 0.11, 0.25, 0.43, 0.67, 1.00, 1.50, and 2.33. After dip coating on glass substrate, coated films were annealed at 200 and 300 °C in air. X-ray diffraction peaks corresponding to crystalline Ag were observed, but a specific peak corresponding to ZrO2 was not observed. At the molar ratio [Ag]/[Zr] = 0.25, the particle size of Ag distributed broadly centered at 17 nm for an annealing temperature of 200 °C and at 25 nm for 300 °C. The films annealed in air at 200 °C showed an absorption band centered at 450 nm because of the silver surface plasmon resonance, whereas films heated at 300 °C in air caused a red shift of the absorption to 500 nm. The absorption peak was analyzed using the effective dielectric function of Ag-ZrO2 composite films modeled with the Maxwell-Garnett expression.

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Chang, Gang, Ichiro Tanahashi, and Munetaka Oyama. "Localized surface plasmon resonance sensing properties of photocatalytically prepared Ag/TiO2 films." Journal of Materials Research 25, no. 1 (2010): 117–23. http://dx.doi.org/10.1557/jmr.2010.0012.

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Photocatalytic deposition of Ag nanoparticles from a mixed aqueous solution of AgNO3 and polyvinylpyrrolidone (PVP) onto TiO2 film supported on indium-tin oxide-coated glass slide (Ag/TiO2 film) was carried out by using UV light irradiation. The size and shape of the Ag nanoparticles were controlled by the addition of PVP during the photodeposition. In the optical absorption spectra of the Ag/TiO2 film, the localized surface plasmon resonance (LSPR) absorption of the Ag nanoparticles was observed. When the film was immersed in various kinds of alcohols with the refractive index at 20°C (), ranging between 1.3292 and 1.4103, the peak LSPR absorption was shifted to longer wavelengths and the peak absorbance increased with increasing . The spectral change of the Ag/TiO2 film with larger spherical Ag nanoparticles was more prominent than that with smaller ones.

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Zhang, Weichun, and Jiyu Fan. "Effect of component volume ratio on the absorption spectra of Ag@Fe3O4 core–shell nanoparticles." Modern Physics Letters B 33, no. 07 (2019): 1950071. http://dx.doi.org/10.1142/s0217984919500714.

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In this paper, we study the absorption efficiency spectra and electric field distribution of Ag nanoparticles enveloped with [Formula: see text] nanoshell by applying the discrete dipole approximation theory. Three kinds of [Formula: see text] core–shell nanoparticles (NPs) structural variables, including the same core with different shell thickness, the same outer shell with different core radius, and the same size of total radius have been discussed in detail. The simulated results show that the localized surface plasmon resonance (LSPR) peak wavelength of NPs is linearly proportional with the volume fraction of the shell, regardless of the outer shell material property and one structural variable. Compared to the plasmon resonance peak of the Ag nanoparticles, the LSPR shift of the NPs is dependent on both the total particles size and the outer [Formula: see text] shell thickness. The electric field around the surface of NPs becomes weaker under the same damping when the core radius decreases. Based on the plasmonic characteristics revealed in this study, it is suggested that it would provide some key guidances for designing the future NPs structural variables for a broad range of plasmon applications.

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Hussain, Talib, Liang Tang, Hui Qi Ye, and Dong Xiao. "Surface Plasmon Effects on Photoluminescence of YAG:Ce³⁺-Yb³⁺." Advances in Science and Technology 98 (October 2016): 32–37. http://dx.doi.org/10.4028/www.scientific.net/ast.98.32.

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Phosphor materials have fascinating applications in the field of photovoltaic and biosensors but low quantum yield is a major hurdle in their applications. In this paper, the influence of surface plasmon on the photoluminescence is investigated with surface modified YAG:Ce3+-Yb3+ coupled with spherical gold nanoparticles. The YAG:Ce3+-Yb3+ photoluminescence band ratio Yb/Ce rise from 0.25 to 0.32 with the plasmon effects. For the photoluminescence, the decay time of Ce reduces from 31.9 ns to 29.9 ns while for Yb from 54.2 ms to 52.0 ms respectively. Further, the plasmon absorption peak is also observed in the spectra of YAG:Ce3+-Yb3+/Au nanoparticles system. The results indicate that the field inside the phosphors has been modulated with surface plasmon of gold nanoparticles.

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36

Yaremchuk, Iryna, Tetiana Bulavinets, Yuriy Smachylo, Yuriy Mysiuk, Volodymyr Fitio, and Pavlo Stakhira. "Modeling of the tunable plasmonic properties of spherical and ellipsoidal silver nanoparticles in the matrix of an organic semiconductor." Technology audit and production reserves 5, no. 1(79) (2024): 12–18. http://dx.doi.org/10.15587/2706-5448.2024.314228.

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The object of research is the tunable plasmonic properties of spherical and ellipsoidal silver nanoparticles in the organic semiconductor matrix. The average absorption cross-sections, scattering cross-sections, and optical radiation efficiency of spherical and ellipsoidal silver nanoparticles have been simulated. The long-wave statistical approach has been used to model the optical parameters of the assembled spherical and ellipsoidal nanoparticles. Statistical averaging is used here, where absorption and scattering are considered from an «effective» particle with statistical properties. This approach avoids complex calculations considering the details of the spectral characteristics of single nanoparticles of different shapes. Taking into account the fact that the nanocomposite matrix will contain ensembles of spherical nanoparticles of different sizes, the peak of their absorption and scattering cross sections will be shifted to the short wavelength region of the spectrum compared to ensembles of the same spherical nanoparticles. In addition, there is a slight increase in the absorption cross-section and a decrease in the scattering cross-section, confirming the presence of smaller nanoparticles. A study was made of a composite material containing a randomly dispersed ensemble of silver ellipsoidal nanoparticles of the same and different shapes and sizes in an organic semiconductor matrix. An ensemble of identical ellipsoidal nanoparticles is characterized by the presence of two plasmon peaks, which corresponds to the characteristics of a single ellipsoidal nanoparticle. A completely different situation is observed if to consider that the nanocomposite will contain an ensemble of ellipsoidal nanoparticles of different shapes and sizes. Such nanoparticles will be characterized by a plasmon peak for both the absorption and scattering cross-sections. This can be explained by the fact that as the size of ellipsoidal nanoparticles decreases, the distance between the peaks responsible for the longitudinal and transverse modes of plasmon excitation decreases. An increase in the shape distribution leads to a broadening of the absorption and scattering cross-section spectra. The efficiency of the optical radiation increases as the size distribution increases. It is shown that a change in the refractive index of an organic semiconductor matrix mainly affects only the value of the scattering cross-section of an ensemble of ellipsoidal nanoparticles dispersed in it. This research is a preliminary step to studying the influence of these particles on the properties of organic light-emitting structures.

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Ban, Gui Jun, Xiu Li Fu, and Zhi Jian Peng. "Gold Nanorods: From Synthesis to Optical Properties." Key Engineering Materials 602-603 (March 2014): 993–97. http://dx.doi.org/10.4028/www.scientific.net/kem.602-603.993.

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Gold nanorods with different aspect ratios, exhibiting localized surface plasmon resonance in a tuned longitudinal mode, were prepared by employing a seed mediated growth approach. Their third-order nonlinear optical properties were investigated by using femtosecond Z-scan technique at 800 nm. All the prepared gold nanorods with different aspect ratios exhibited a reverse saturation absorbance behavior, and the value of effective nonlinear absorption coefficient reaches its maximum when the longitudinal surface plasmon resonance peak of the gold nanorods located near the excitation wavelength.

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38

Heidari, Alireza, Angela Caissutti, Maria Henderson, et al. "Recent New Results and Achievements of California South University (CSU) BioSpectroscopy Core Research Laboratory for COVID-19 or 2019-nCoV Treatment: Diagnosis and Treatment Methodologies of “Coronavirus”." Journal of Current Viruses and Treatment Methodologies 1, no. 1 (2020): 3–41. http://dx.doi.org/10.14302/issn.2691-8862.jvat-20-3275.

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Coronavirus nanoparticles show a strong peak of Plasmon absorption in ultraviolet–visible zone. A strong interaction exists between the surface of Coronavirus nanoparticles and Bcr–Abl tyrosine–kinase inhibitors (TKI) such as Imatinib (STI571), Nilotinib (AMN107), Dasatinib (BMS–345825), Bosutinib (SKI–606), Ponatinib (AP–24534) and Bafetinib (INNO–406). Bcr–Abl tyrosine–kinase inhibitors (TKI) such as Imatinib (STI571), Nilotinib (AMN107), Dasatinib (BMS–345825), Bosutinib (SKI–606), Ponatinib (AP–24534) and Bafetinib (INNO–406) cause to aggregation of Coronavirus nanoparticles linked to DNA/RNA and hence, lead to widening of peak Plasmon of Coronavirus nanoparticles surface at 550 (nm) and emerging a new peak at higher wavelength. In the current project, this optical characteristic of Coronavirus nanoparticles is used to time investigate of interaction between different Bcr–Abl tyrosine–kinase inhibitors (TKI) such as Imatinib (STI571), Nilotinib (AMN107), Dasatinib (BMS–345825), Bosutinib (SKI–606), Ponatinib (AP–24534) and Bafetinib (INNO–406) and Coronavirus nanoparticles. The results were shown that Bcr–Abl tyrosine–kinase inhibitors (TKI) such as Imatinib (STI571), Nilotinib (AMN107), Dasatinib (BMS–345825), Bosutinib (SKI–606), Ponatinib (AP–24534) and Bafetinib (INNO–406) with shorter chain length interact faster with Coronavirus nanoparticles. Therefore, a simple and fast method for identification of Bcr–Abl tyrosine–kinase inhibitors (TKI) such as Imatinib (STI571), Nilotinib (AMN107), Dasatinib (BMS–345825), Bosutinib (SKI–606), Ponatinib (AP–24534) and Bafetinib (INNO–406) with various chain length using red shift in surficial Plasmon absorption is presented.

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Gusrizal, Gusrizal, Sri Juari Santosa, Eko Sri Kunarti, and Bambang Rusdiarso. "Two Highly Stable Silver Nanoparticles: Surface Plasmon Resonance Spectra Study of Silver Nanoparticles Capped with m-Hydroxybenzoic Acid and p-Hydroxybenzoic Acid." Molekul 13, no. 1 (2018): 30. http://dx.doi.org/10.20884/1.jm.2018.13.1.424.

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Silver nanoparticles capped with m-hydroxybenzoic acid and p-hydroxybenzoic have been successfully synthesized, but the long-term stability data of these silver nanoparticles are not available. In this paper, we report the stability of these two types of silver nanoparticles for a period of 40 weeks observation based on the change of surface plasmon resonance spectra of silver nanoparticles. Silver nanoparticles were synthesized by reduction of silver nitrate with m-hydroxybenzoic acid and p-hydroxybenzoic acid without addition of capping agent. The presence of silver nanoparticles was indicated by the appearance of yellow color due to the surface plasmon resonance of silver nanoparticles. The resulted silver nanoparticles were stored at room temperature and further UV-visible spectrophotometer was used to follow the change in surface plasmon resonance spectra. The surface plasmon resonance spectra of silver nanoparticles were overlapped for the first 18 weeks, followed by little change in the position of absorption maxima (lmax), peak intensity, and width of the absorption peak until the week of 40. Silver nanoparticles capped with m-hydroxybenzoic acid and silver nanoparticles capped with p-hydroxybenzoic acid were highly stable which should make them suitable for further applications. The results show the potential of m-hydroxybenzoic acid and p-hydroxybenzoic acid to become a new reducing agent in the synthesis of highly stable silver nanoparticles. The m-hydroxybenzoic acid and p-hydroxybenzoic acid appeared to act as both reducing and capping agent.

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40

Choi, Jae-Youn, Wenguo Dong, Dong Joo Choi, Chong S. Yoon, and Young-Ho Kim. "Thermal Stability of Cu and Cu2O Nanoparticles in a Polyimide Film." Journal of Nanoscience and Nanotechnology 8, no. 9 (2008): 4822–25. http://dx.doi.org/10.1166/jnn.2008.ic14.

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Nanoparticles of Cu or Cu oxide dispersed in a polyimide (PI) film were fabricated by reaction of polyamic acid with a thin Cu film during imidization. In this paper, the thermal stability of the Cu or Cu oxide nanoparticles was investigated under various atmospheres. The PI/nanoparticle composites were heat-treated at 140 °C and 250 °C in air, N2, Ar, and 5% H2 atmospheres. Nanoparticles in the PI film were characterized by UV-VIS spectroscopy and transmission electron microscopy. The optical absorption peaks originating from Cu or Cu2O nanoparticles were changed by heat-treatment in different atmospheres. When Cu nanoparticles were oxidized by heat-treatment in air, the surface plasmon resonance (SPR) peak originating from the Cu nanoparticles disappeared. The quantum confined absorption peak of Cu2O was not affected by heat-treatment in N2 or Ar. Cu2O nanoparticles were reduced by heat-treatment at 250 °C in 5% H2 atmosphere and a new SPR peak appeared. Our results show that Cu nanoparticles are easily oxidized and highly dense Cu nanoparticles can be formed by reducing Cu2O nanoparticles.

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41

Pecharromán, Carlos. "Influence of the close sphere interaction on the surface plasmon resonance absorption peak." Physical Chemistry Chemical Physics 11, no. 28 (2009): 5922. http://dx.doi.org/10.1039/b902489c.

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42

Tanahashi, I., M. Yoshida, Y. Manabe, and T. Tohda. "Effects of heat treatment on Ag particle growth and optical properties in Ag/SiO2 glass composite thin films." Journal of Materials Research 10, no. 2 (1995): 362–65. http://dx.doi.org/10.1557/jmr.1995.0362.

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Small Ag particles were embedded in SiO2 glass thin films by a multi-target sputtering method. The mean diameter of Ag particles in the as-deposited film with 28.0 at. % of Ag was estimated to be 4.4 nm and it was increased to 24.0 nm when the film was heat-treated at 700 °C for 3 h. The diameter was proportional to the cube root of the heat-treatment time, suggesting that the Ag particles grew in the supersaturated solid solution. In the optical absorption spectra of the heat-treated films, the absorption peak due to the surface plasmon resonance of Ag particles was observed about 410 nm. The peak intensity became large and the full width at half maximum of the absorption band was decreased with increasing the diameter of Ag particles.

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43

Shuba, Mikhail, Gintaras Valušis та Vasil Saroka. "Ultraviolet π-Plasmon Contribution to the Transverse Optical Response of Doped Single-Walled Carbon Nanotubes". Phys. Rev. B 109, № 16 (2024): 165409. https://doi.org/10.5281/zenodo.15034014.

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A model for the effective permittivity of a doped single-walled carbon nanotube (CNT) thin film in the optical range is proposed. The permittivity of CNT walls is calculated from the quantum theory of 𝜋-electron transitions. The contributions from 𝜎 electrons and ultraviolet 𝜋 plasmon are taken into account phenomenologically using experimental data obtained for graphene and CNT film. These contributions lead to an enhancement of the depolarization effect thereby strongly suppressing the transverse response of the CNTs. They also cause a decrease in both the frequency and height of the absorption peak associated with the azimuthal intersubband plasmon in doped CNTs. This eliminates the existing discrepancy between experimental and previous theoretical data. The azimuthal plasmon response is studied in a bundle of doped CNTs.

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Zhou, Ziji, Hongyu Lin, Xiaohang Pan, et al. "Surface plasmon enhanced InAs-based mid-wavelength infrared photodetector." Applied Physics Letters 122, no. 9 (2023): 091105. http://dx.doi.org/10.1063/5.0140370.

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High performance photodetectors operating in the mid-wavelength infrared spectral range are of great significance in many applications such as defense, surveillance, gas sensing, and night vision. A key parameter in the design of infrared detectors is the thickness of the absorber layer; reaching high absorption with a thin absorber layer can significantly enhance the performance of the device. In this work, we demonstrate the enhancement of InAs-base infrared detectors using surface plasmon nanostructures. Experimental results show that our device exhibits broadband enhancement compared to the reference with an increase in peak responsivity of about 50%. Further analysis shows that the enhancement of the device is attributed to the near-field localization effect of the plasma structure, which is well demonstrated by the experimental dual-peak spectrum. Such mechanisms provide valuable insight into the plasmon-enhanced infrared photodetector.

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45

Feng, Hefa. "Resonant Excitation Analysis of the Absorption Enhancement of L-Shaped Metasurfaces in Midinfrared Band." Journal of Sensors 2022 (August 11, 2022): 1–9. http://dx.doi.org/10.1155/2022/1571023.

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Surface plasmon waveguides have attracted a lot of attention in recent years due to their ability to conduct light in the subwavelength scale. A large number of metallic structures have been used as waveguides and applied in integrated photonic circuits. Among these structures, the metal-insulator-metal surface plasmon waveguide is considered to have unique advantages. Compared to other waveguide forms, it is more compact and thus easier to integrate into optical circuits. For these reasons, we investigated the transmission properties of surface plasmon waves in metal-insulator-metal waveguides and built a MIM absorber consisting of gold and dielectric. We developed an interference model for the MIM absorber and concluded that the interactions between the metal patch and the substrate are not negligible in the near field. In addition, magnetic resonance plays an equally important role in approaching uniform absorption. Absorption spectra with different structural parameters, incidence angles, and polarizations were investigated. A sharp absorption peak was also found to be caused by the Rayleigh anomaly. The study reported in this paper contributes to further understanding of the physical properties of the MIM absorber, and we expect to refine the theoretical model in the future to eliminate the bias caused by near-field coupling.

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Ju, Seongmin, Viet Linh Nguyen, Pramod R. Watekar, et al. "Fabrication and Optical Characteristics of a Novel Optical Fiber Doped with the Au Nanoparticles." Journal of Nanoscience and Nanotechnology 6, no. 11 (2006): 3555–58. http://dx.doi.org/10.1166/jnn.2006.17981.

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Optical fibers containing gold metal nanoparticles were developed by modified chemical vapor deposition, in which Au(OH)3 and tetraethyl-orthosilicate (TEOS) was used via sol–gel process to incorporate gold metals by providing the reduction atmosphere. The absorption peak appeared near 490 nm was found to be due to the surface plasmon resonance of the gold nanoparticles incorporated in the fiber core.

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Jiang, Xinpeng, Zhaojian Zhang, Kui Wen, Guofeng Li, Jie He, and Junbo Yang. "A Triple-Band Hybridization Coherent Perfect Absorber Based on Graphene Metamaterial." Applied Sciences 10, no. 5 (2020): 1750. http://dx.doi.org/10.3390/app10051750.

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In this paper, a triple-band hybridization coherent perfect absorber based on graphene metamaterial is proposed, which consists of graphene concentric nanorings with different sizes and a metallic mirror separated by SiO2 layer. Based on the finite-difference time-domain (FDTD) solution, triple-band coherent perfect absorption is achieved at frequencies from 0.6 THz to 1.8 THz, which results from the surface plasmon resonance hybridization. The wavelength of the absorption peak can be rapidly changed by varying the Fermi level of graphene. Most importantly, the wavelength of the absorption peak can be independently tuned by varying the Fermi level of the single graphene nanoring. Moreover, the triple hybridization perfect absorber is angle-insensitive because of the perfect symmetry structure of the graphene nanorings. Therefore, our results may widely inspire optoelectronic and micro-nano applications, such as cloaking, tunable sensor, etc.

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Yaremchuk, I., T. Bulavinets, P. Stakhira, and V. Fitio. "NANOCOMPOSITE MATERIALS BASED ON GRAPHENE, GRAPHENE OXIDE, AND SILVER NANOPARTICLES." Information and communication technologies, electronic engineering 3, no. 1 (2023): 163–69. http://dx.doi.org/10.23939/ictee2023.01.163.

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In this work, plasmon characteristics of nanocomposite materials based on graphene, graphene oxide, and silver nanoparticles have been studied. The effective dielectric constant and absorption coefficient of the nanocomposites based on graphene-silver and graphene oxide – silver depending on the concentration and size of nanoparticles have been calculated. A change in the silver nanoparticles filling factor by 5 percent leads to significant changes in both the real and imaginary parts of the effective dielectric constant of the nanocomposite material. A pronounced absorption peak is observed in the case of graphene-based nanocomposite with a silver filling factor of 0.2. At the same time, the absorption peak can be indicated at a silver filling factor of 0.1 for the graphene oxide-based nanocomposite. The maximum absorption is observed for the nanocomposite material with nanoparticles having a radius of 5 nm in both cases. The researched nanocomposite materials can be successfully used for various organic electronics applications.

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Ouyang, F., and M. Isaacson. "Observation of the quantum size effect in the STEM." Proceedings, annual meeting, Electron Microscopy Society of America 47 (August 6, 1989): 230–31. http://dx.doi.org/10.1017/s0424820100153129.

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The study of small particles or microclusters has been very active in recent years. When the particle size becomes smaller, its electronic properties deviate from those of bulk material and become size dependent. This phenomenon is refered to as the quantum size effect.One of the frequently used probes for studying the electronic states of small particles is the surface plasmon (SP) excitation. Genzel et al. studied the optical absorption peaks from silver particles in glass. They found a blue shift of the SP peak when the particle size becomes smaller (see Fig 2). Electron energy loss spectroscopy (EELS) studies have also been performed. Recently vom Felde et al. reported broad beam EELS with large momentum transfer from potassium particles embedded in a MgO matrix. They observed that the surface plasmon energy increases when particle size becomes smaller, and there is a positive dispersion for particles of size 40 Å.

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Liu, Xingsheng, Lijun Dong, and Shouzhi Pu. "A thermally tunable single-band metamaterials with VO2 disks based on localized surface plasmon resonance." Materials Express 9, no. 7 (2019): 704–11. http://dx.doi.org/10.1166/mex.2019.1528.

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A thermal tunability metamaterial absorber with single-band absorption properties is proposed and numerical verification. An absorption peak can be revealed at resonant wavelength 1.54 m at room temperature. The metal parameter condition is optimized in simulation in order to improve the property of this absorber. Simulated results reveal that absorption performances can be modulated based on the refractive index changes. High FOM values are obtained based on water or glucose solution. Moreover, the resonance wavelength and amplitude are modulated based on the ambient temperature changes. Finally, the effect of central metal particle side width or dielectric layer thickness at room temperature on absorption performances are also revealed in simulation.

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Journal articles on the topic 'Peak Plasmon Absorption'

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