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1
Zhou, JianBin. "Electrical Characteristics of Aged Composite Insulators". Queensland University of Technology, 2003. http://eprints.qut.edu.au/16086/.
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Composite insulators are widely being used in power industry to alternate traditional porcelain-based insulators for their advantages, including better pollution performance, low maintenance cost, light weight, compact line design. However, due to the short application history and experience, the degradation of composite insulators in natural environment is a big concern for the power utilities. The knowledge on the degradation of composite insulators is being studied world wide. The methods to assess the working conditions of composite insulators are being studied and created. In Queensland University of Technology (QUT), the approach based on chemical analysis methods was first developed. The work in this thesis based on the previous research work is focused on correlating electrical characteristics with chemical analysis results of the composite insulators and physical observations results. First,the electrical characteristics of composite insulators were presented and analysed, including leakage current, cumulative current, peaks of leakage current, the statistic results of the leakage current. Among them, the characteristics of leakage current were mainly studied. The shape of waveforms was found to relate to the degree of discharge activities of the composite insulators. The waveforms analysed by FFT revealed that the odd harmonic components became obvious during the discharge activities. The correlations between the electrical characteristics of composite insulators and chemical analysis results showed that the composition of composite insulators plays significant roles in terms of electrical performance. The oxidation index (O.I.) and the ester/ketone ratio (E/K) differentiated the different degradation reasons of the composite insulators in the test conditions. Finally, the thesis presents one approach, which aims to assess the surface conditions of composite insulators in an easy manner and in short time.
2
Senthinathan, Ramesh 1961. "ELECTRICAL CHARACTERISTICS OF INTEGRATED CIRCUIT PACKAGES". Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276425.
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Xu, Kemu. "Simulation of Electrical Characteristics in Oxyfuel Flame Subject to An Electric Field". Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/103816.
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The oxyfuel cutting method is still widely used nowadays, even though it is not a fully autonomous
process. Thisthesis presents a computational model to study ion and electron transport and current-voltage characteristics inside a methane-oxygen flame. By finding the relationship between
current-voltage characteristics and critical parameters,such as standoff, fuel oxygen ratio, and flow
rate, a control algorithm could be implemented into the system and make it autonomous. Star
CCM+ software is used to develop preheat phase computational models by splitting the
simulations into the combustion and electrochemical transport parts. Both the laminar and
turbulent flows are considered. Several laboratory experiments are used to compare test data with
the numerical results generated using this model. The initial and boundary conditions used in the
simulation were to the extent possible similar to the experimental conditions in the laboratory
experiment.
In the combustion part, the general GRI3.0 mechanism plus three additional ionization reactions
are applied, and the combustion part results are then used as input into the electrochemical
transport part. A particular inspection line inside the domain is created to analyze the results of the
electrochemical transport part. Ions, electrons number density, and current density are studied in
the interval from -40V to 40V electric potential. The ions are heavier and more challenging to
move than electrons. The results show that at both the torch and work surfaces, charged sheaths
are formed, which cause three different regions of current-voltage relations to form in a similar
manner as observed in the tests.Master of Science
Oxyfuel cutting is essential to numerous industries, such as shipbuilding, rail, earth moving equipment, commercial building construction, etc. Tuning the process parameters and diagnosing problems with the oxyfuel process still relies on experienced operators. The main obstacles to the automation of the oxyfuel process come from the limitations of the sensing suites currently in use. Since typical sensors are highly unreliable in the harsh environment near the high-temperature flame, an alternate method is proposed to find the co-dependence between the flame's electrical characteristics and critical parameters of the oxyfuel cutting system (standoff, flow rate, F/O ratio, etc.). The relevant electrical characteristics are the electrical potential and distribution of ions and electrons. Two-dimensional models are created to analyze the combustion of methane-oxygen flame and transport of ions and electrons. The models allow the derivation of the current-voltage characteristic between the torch and work surface. Also, the way sheath phenomena of ions and electrons on the surface affect the current-voltage relationship can be analyzed from ions and electrons distribution. The electric field is added to the model by applying a constant voltage to the torch tip surface. To validate the models, a laboratory experiment with a similar geometry arrangement is used as a comparision. The models' results reveal three different regimes in the current-voltage relationship.
4
Dawei, Jiang. "Electrical and optical characterization of InP nanowire-based photodetectors". Thesis, Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-25733.
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This thesis deals with electrical and optical characterization of p+i–n+ nanowire-based photodetectors/solar cells. I have investigated their I-V performance and found that all of them exhibit a clear rectifying behavior with an ideality factor around 2.2 at 300K. used Fourier transform infrared spectroscopy to extract their optical properties. From the spectrally resolved photocurrent data, I conclude that the main photocurrent is generated in the i-segment of the nanowire (NW) p-i-n junctions, with negligible contribution from the substrate. I also used a C-V technique to investigate the impurity/doping profiles of the NW p+-i-n+ junction. The technique has been widely used for investigations of doping profiles in planar p-n junctions, in particular with one terminal (n or p) highly doped. To verify the accuracy of the technique, I also used a planar Schottky sample with an already known doping profile for a test experiment. The result is very similar to the actual data. When we used the technique to investigate the doping level in the NWs photodetectors grown on InP substrates, the results show a very high capacitance above 800pF which most likely is due to the influence of the parasitic capacitance from the insulating layer of SiO2. Thus, a new sample design is required to investigate the doping profiles of NWs.
5
Jennison, Katy. "The electrical charge characteristics of muscle proteins". Thesis, University of Oxford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304488.
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Reid, William B. "The electrical characteristics of lithium silicate glasses". Thesis, University of Aberdeen, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328008.
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The electrical behaviour of a series of lithium silicate glasses has been characterised by the versatile a.c. impedance technique. The advantage of using a combination of complex plane and spectroscopic plots in the data analysis is shown. The compositional dependence of the conductivities of the phase separated glasses, which exhibit complex two-phase spinodal decomposition or nucleation and growth textures, is related to the volume fraction of the phases present in the conduction pathway and the tortuosity of the effective medium. The compositional dependence of the conductivities of homogeneous lithium silicate glasses is accounted for by postulating a glass structure composed of silicate anion clusters which are surrounded by a lithia-rich phase which constitutes the preferred conduction pathway. Annealing effects are also reported. The effect of surface roughness on the response of the electrode/electrolyte interface, a phenomenon originally reported by de Levie, and contact problems between the metal electrode and the glass electrolyte are discussed. Novel results regarding the effect of gold electrode recrystallisation on the a.c. response of glass electrolytes are reported. The a.c. impedance technique is shown to be a very useful, surface sensitive tool for monitoring interfacial phenomena such as atmospheric corrosion and surface ion-exchange. The technique is also successfully applied to studies of the mechanism of glass-ceramic formation, where the identification of surface crystallisation products and residual glass, by electrical measurement, is possible. Conclusive evidence for the presence of an effective medium conduction mechanism (percolation theory) in the inhomogeneous glass-ceramic, is given. The electrical data are corroborated by electron microscopy, x-ray diffractometry, energy dispersive x-ray analysis and Fourier Transform Infrared Spectroscopy.
7
Okazaki, Tomohisa. "Characteristics of Electrical Anisotropy in Magnetotelluric Responses". Kyoto University, 2018. http://hdl.handle.net/2433/232256.
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Haarpaintner, Guido. "Electrical characteristics of quantum well solar cells". Thesis, Imperial College London, 1995. http://hdl.handle.net/10044/1/7609.
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Thong, Aaron. "Electrical characteristics of single molecule fullerene based devices". Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/49253.
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This thesis investigates the design of a unimolecular donor-acceptor system (4TPA-C60) for the purpose of developing biomimetic Turin IETS sensors. The gas phase 4TPA-C60 molecule is calculated to have a localised double-well electronic structure, which is similar to that of a nanowire resonant tunnelling device. 4TPA-C60 decorated gold surfaces are prepared from scratch, and characterised at each step. STM imaging confirms successful grafting of the molecular species to the gold surface. Scanning tunneling spectroscopy performed on these molecular double-barrier tunnel junctions show a slightly asymmetric I(V ) profile, similar to predictions from ab initio calculations. DFT calculations also reveal that the behaviour of the device is strongly dependent on the supramolecular couplings at both metal/molecule interfaces. A new phenomenon is identified, where pinning of the LUMO to the HOMO states maintains the resonant transmission channel and prevents crossing of the frontier molecular orbitals at higher biases. The HOMO-LUMO pinning effect is determined to arise from charge accumulation on the C60 cage, due to smaller coupling at the C60/metal interface. By preventing crossing of the states, HOMO-LUMO pinning delays the onset of the NDR feature, resulting in a wider current peak and lower resolution of the sensor. Based on the charge transport mechanism, several alternative systems are proposed in which HOMO-LUMO pinning can be minimized. An endohedral fullerene derivative, 4TPA-F@C60, is found to be the most promising candidate, displaying much narrower NDR peaks. These findings not only help to improve future designs of molecular Turin IETS sensors, but also contribute significantly to our understanding in the broader field of molecular devices in general.
10
Afacan, Gonenc. "The Electrical Characteristics Of Antennas In Their Operational Environment". Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/2/12609119/index.pdf.
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This thesis investigates the variations of electrical properties of linear antennas mounted on certain platforms, depending on the physical properties of that platform. In this respect, related basic antenna simulations, electromagnetic simulations from primitive to complex models of airframes, and scale model measurements were used.
Firstly, electrical properties of monopoles at known environment were examined and basic analyses were performed via an electromagnetic simulation tool, named CST Microwave Studio®. In addition, important aspects of simulation tool were investigated. Then, an F-4 aircraft model was used to observe the electrical characteristics of antennas mounted on it. Using 3D model of F-4 aircraft, realistic antenna placement points were assigned and monopoles were attached to those points. Alternatively, a simplified F-4 model was also used and for two different models, identical simulations were done, followed by accuracy and performance analysis between the results obtained from simplified and exact models. As the outcome of these simulations, certain parameters like impedance, antenna-to-antenna coupling and radiation pattern values were examined. Additionally, change in antennas&rsquo
electrical characteristics due to their position over the airframe was investigated. In addition, a 1:10 down-scaled and copper-plated F-4 aircraft model was obtained and equipped with identical antennas. By using the measurements done on this scale model, antenna-to-antenna coupling results of MWS®
were verified by measurements. Finally, advantages and disadvantages of using electromagnetic simulation tools and scale model measurements for such antenna studies were discussed.
11
Hasbullah, Nurul Fadzlin. "Optical and electrical characteristics of quantum dot laser structures". Thesis, University of Sheffield, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.522006.
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Majlis, Burhanuddin bin Haji Yeop. "Electrical characteristics of SRO-miss devices and their applications". Thesis, Durham University, 1988. http://etheses.dur.ac.uk/6322/.
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The electrical characteristics of the Metal-Insulator-Semiconductor - Switch (MISS) device with Silicon-Rich-Oxide (SRO) as the semi-insulating material have been comprehensively studied at room temperature in an exploratory way. The SRO films were deposited by atmospheric pressure chemical vapour deposition (APCVD) at 650ºC with SiH(_4) and N(_2)O reactant gases and N(_2) carrier. The react ant gas phase ratio R(_o) varying from 0.09 to 0.25 and the deposition time varying from 0.6 to 2 min. Some preliminary investigations on SRO-MIS devices were also carried out in order to understand the electronic process in the structure. Various parameters which governed the switching behaviour of an MISS were investigated. In general the switching characteristics are similar to those of the tunnel oxide MISS. The geometrical dependence of the switching behaviour in the tunnel oxide MISS has been extended to the present device by looking at the effects of electrode area, junction area, electrode perimeters and of a metal guard ring. Other effects, such as SRO deposition time, work function difference, gold doping, heat treatment, light illumination and film ageing were also observed. The dynamic characteristic of the device was studied using a double pulse technique. The characteristics of the three-terminal SRO-MISS were studied in both forward and reverse bias. The former exhibited a thyristor-like characteristic and the latter a transistor-Hke characteristic. A preliminary study on the MIS-emitter transistor was carried out with different emitter areas. In general the characteristics are the same as for the equivalent tunnel oxide devices. However it was also found that if the n-type epilayer is very thin the transistor characteristics exhibits an N-type negative resistance. The negative resistance region of the two-terminal MISS has been shown to be stable and the stability has been analysed in terms of equivalent circuit elements. The reason for the stability is that the device also has an negative capacitance. This has been proved experimentally and it is a new property of the MISS structure which never been reported before. The negative capacitance has been measured as a function of electrode area, SRO type and light illumination. An important circuit application for the negative capacitance has also been suggested and demonstrated
13
Davies, Luke. "A cellular model of the electrical characteristics of skin". Thesis, University of Southampton, 2018. https://eprints.soton.ac.uk/423466/.
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The dielectric properties of skin are of particular interest in the fields of Functional Electrical Stimulation (FES), diagnostic procedures such as Electrocardiogram and cancer treatment. This thesis is concerned primarily with the effect of hydration and electroporation on skin impedance when signals used in FES are applied. Skin impedance has typically been represented by an equivalent circuit of varying complexities in the literature; however this approach does not incorporate the effects of hydration and electroporation. Alternatives to this include simulation of skin cells undergoing electrical stimulation and direct experimentation either in vitro or in vivo. This thesis aims to expand the current understanding in this field with particular focus on the effects of hydration and electroporation through simulation. The stratum corneum (SC) has the most dominant impact on overall impedance of skin, particularly at low frequencies, and therefore was the focus for all of the simulations. The models representing individual cells showed strong agreement with experimental data in the literature in terms of their impedance when exposed to a variety of frequencies and input voltages. Expanding these models to include a greater number of cells continued to generate agreement with experimental data from the literature. When the conductivity of the SC cells were altered to represent the effect of hydration, the simulations showed a substantial reduction in impedance from 53kΩ to 27kΩ, which can be represented as a double exponential decay. A further model was produced with a cell membrane conductivity dependent upon the voltage across the membrane to represent the presence of electropores. The results showed that when signals typically used in FES are applied, electropores are formed. The presence of electropores causes a decrease in skin impedance from 76kΩ to 22kΩ.
14
Van, den Berg Claire Barbara. "Structural and electrical characteristics of printed metal nanoparticle networks". Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/22914.
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The structural and electrical properties of metal nanoparticle (NP) networks and their dependence on the constituent phases have been investigated. Percolation and effective media theories have been used to describe the physical properties of disordered systems, as well as providing a link between their structural features and the corresponding electrical transport properties. Silver and palladium nanoparticulate layers in ethyl cellulose polymer binder (ETHOCELTM), were fabricated onto paper using the method of screen printing. The metal-binder ratios were varied in order to observe changes in the microstructure when a percolating network consisting of the metal NPs is formed through the layer.
15
Crawford, Brian Patrick. "Characteristics of multi-h coded modulation". Master's thesis, University of Cape Town, 1994. http://hdl.handle.net/11427/9646.
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Includes bibliographical references (leaves 74-75).Multi-h Coded Continuous-Phase Frequency Shift Keying (Multi-h CPFSK) has gained interest in recent years because it offers an additional degree of freedom in the coding of CPFSK. Similar to Trellis Coded Modulation (TCM), it does not use redundancy to achieve coding gain. Hence with properly chosen modulation indices, impact to spectral occupancy is kept to a minimum. While there has been less attention given of this method as compared with TCM, this method can also be used with data coding. In cases where data coding is to be implemented, simultaneous use of Multi-h coding can be implemented with very little increase in complexity. In this thesis, a thorough mathematical review of this technique is made. A multi-oscillator multih coded modulator is shown similar to one presented by Massey for MSK. A unique analytical tool called a multi-oscillator trellis is presented. This considers the phase transitions with respect to each of the signalling frequencies instead of the center frequency, f₀. The multi-oscillator trellis is used to determine the state machine that will switch a bank of oscillators. The purpose of the state machine is to maintain continuous phase at the multi-oscillator output while generating the proper signal frequencies according to the data and modulation index. The Maximum Likelihood Detection process at the receiver is shown as a partition of an uncoded CPFSK signal. Finally, an analysis is made to determine if a modulator with a non-linear frequencyvoltage characteristic is suitable in a coherent multi-h coded application. Much of the literature on this topic has been comparative to PSK. It is the intent of this work to use FSK and MSK as the baseline to determine how existing structures may be extended to realize the benefits of multi-h coding. The application of this coding to an 8 Mbps 23 GHz CPFSK point-to-point terrestrial communications system is also a topic of this thesis. It is in this context that the analysis is made.
16
Li, Feng 1967. "Characteristics of CuInSe₂ homojunction photodetectors". Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=31057.
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Studies have been made on homojunction photodetectors fabricated on Bridgman-grown monocrystalline p-type CuInSe2 substrates by diffusion of indium. The essential steps required to optimize the fabrication conditions were established.Firstly, parameters such as quantum efficiency, junction depth, surface recombination velocity, and minority carrier diffusion length are analyzed. Secondly, the dark current-voltage characteristics of devices were measured. Some detector dark current is only 80nA at 0.5V reverse bias. It was confirmed that the diffusion current and recombination current are comparable in the dark current transport mechanism of the CuInSe2 homojunctions. Thirdly, the relationships between capacitance-voltage, capacitance-frequency characteristics were also investigated. It was observed that at a given voltage, the capacitance value decreased when the measuring frequency was increased. This result confirmed that deep defects exist in the material. Fourthly, the diffusion length of minority carriers was determined by the photocurrent and capacitance method. The diffusion length is smaller than 1 micron. The quantum efficiency and photoresponse were also measured. The maximum quantum efficiency of the detectors was measured as high as 60%. The photodetector response time range from 14 mus to 21 mus.
17
Amin, Mohammed y Md Obaidul Alam. "Electrical and optical characteristics of InP interband nanowire infrared photodetectors". Thesis, Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-6219.
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We have investigated two devices for detection of radiation, typically in the infrared range, Photons are absorbed in an active region of semiconductor devices such that the absorption induces inter band electronic transitions and generate photo-excited charge carriers. A photocurrent is generated between the conducting contacts through the active region of the devices. We worked on infrared photodectors based on nanowires. This type of photodectors can be used for optical communication and to detect atmospheric pollution by absorption of the polluting molecules in the infrared region (0.7µm-1µm). In this project we have used Fourier transform infrared spectroscopy to study and compared the photoresponse of two different types of interband nanowire infrared photodetectors 8samples 6080 and 6074). Fourier Transform infrared (FTIR) spectroscopy is a measurement technique that allows one to record infrared spectra in all wavelengths at then same time. The basic task was to compare and analyse the electrical and optical characteristics of these two detectors at different temperatures (78K-300K) corresponding to the wavelength.
18
Zhang, Hui. "Aging characteristics of solid polymeric materials used for electrical insulation". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0018/MQ52685.pdf.
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Kouadria, Djilali. "The ageing and breakdown characteristics of electrical machine insulation materials". Thesis, University of Brighton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.264002.
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Park, Sung-Hoon. "Electrical, electromagnetic and structural characteristics of carbon nanotube-polymer nanocomposites". Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3386926.
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Thesis (Ph. D.)--University of California, San Diego, 2009.Title from first page of PDF file (viewed February 8, 2010). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 74-85).
21
Dynes, Scott Budd Chapman. "Discharge characteristics of auditory nerve fibers for pulsatile electrical stimuli". Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/11194.
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Johnson, Jeremy D. "Characteristics of a multipole volume H-plasma". Thesis, Aston University, 1987. http://publications.aston.ac.uk/8076/.
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23
Yang, Shaoyong. "Cryogenic characteristics of IGBTs". Thesis, University of Birmingham, 2005. http://etheses.bham.ac.uk//id/eprint/896/.
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Applications are now starting to emerge for superconducting devices in the areas of electrical power conversion and management, for example superconducting windings for marine propulsion motors, superconducting fault current limiters and superconducting magnet energy storage (SMES). Many of these applications also require power electronics, and it is therefore timely to consider the possibility of locating the power electronics in the cryosystem with the superconducting devices. Although significant work has been undertaken on the cryogenic operation of small devices, little has been published on larger devices, particularly the IGBT. This therefore forms the focus of this study. To examine the cryogenic performance of the sample devices, a cryo-system consisting of a cold chamber, a helium-filled compressor and vacuum pumps was built. Static, gate charge and switching tests were carried out on three types of IGBT modules, PT (punch-through), NPT (non-punch-through) and IGBT3 respectively, in the temperature range of 50 to 300 K. The switching tests were undertaken at 600V and up to 110 A. A physically based, compact level-1 model was selected to model the cryogenic performance of the IGBTs. A generic Saber power diode model with reverse recovery was selected to model the diode cryogenic performance. Close correspondence was demonstrated between the models and experimental results over the temperature range of 50- 300 K. Saber simulation was used to examine the cryogenic performance of a DC-DC step-down converter and a pulse-width modulated inverter leg, in which the temperature-dependent power device models developed in the modelling work were used. The simulation results showed that standard power electronic circuits using standard devices could work much more efficiently at low temperatures, for example, the efficiency of the DC-DC converter working at 50 kHz being increased from 90.0% at room temperature to 97.0% at 50 K.
24
Courey, Karim Joseph. "An Investigation of the Electrical Short Circuit Characteristics of Tin Whiskers". Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_dissertations/38.
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Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that has a currently unknown probability associated with it. Due to contact resistance electrical shorts may not occur at lower voltage levels. In these experiments, the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit was studied. From this data, the probability of an electrical short was estimated, as a function of voltage, given that a free tin whisker has bridged two adjacent exposed electrical conductors. Also, three tin whiskers grown from the same Space Shuttle Orbiter card guide used in the aforementioned experiment were cross-sectioned and studied using a focused ion beam (FIB). The rare polycrystalline structure seen in the FIB cross section was confirmed using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size of each card guide's tin plating to determine its finish.
25
Chang, Tsu y 張慈. "Electrical Characteristics of thin oxide". Thesis, 1997. http://ndltd.ncl.edu.tw/handle/43355836550523123070.
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碩士國立交通大學
電子工程學系
85
We have studied the inversion layer mobility of n-MOSFET's with thin oxide of 2-7nm.Direct relationship of electron mobility tointerface roughness was obtained from the measured mobility of MOSFET'sand high-resolution TEM.By using low-pressure oxidation process with nativeoxide removed in-situ prior to oxidation, atomically smooth interface ofoxide/Si can be observed by high- resolutional TEM for oxide thicknessof 1.1 and 3.8nm.The roughness increased to 1-2 monolayers of Si in a 5.5nmoxide. Because of the smooth interface and good thickness uniformity ofoxide,both high-field electron mobility and oxide breakdown behaviorare much improved.Significant mobility improvement is obtained from theseoxides with smoother interface than that from conventional furnace oxidation.Mobility reduction in ultra-thin oxide was observed for the first time,which may be due to the remote Coulomb scattering from gate electrode.
26
Wang, Hao. "Power MOSFETs with Enhanced Electrical Characteristics". Thesis, 2009. http://hdl.handle.net/1807/24329.
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The integration of high voltage power transistors with control circuitry to form smart Power Integrated Circuits (PIC) has numerous applications in the areas of industrial and consumer electronics. These smart PICs must rely on the availability of high performance power transistors. In this thesis, a vertical U-shaped gate MOSFET (UMOS) and a lateral Extended Drain MOSFET (EDMOS) with enhanced electrical characteristics are proposed, developed and verified via experimental fabrication. The proposed new process and structure offers superior performance, such as low on-resistance, low gate charge and optimized high breakdown voltage.
In the vertical power UMOS, a novel trenched Local Oxidation of Silicon (LOCOS) process has been applied to the vertical gate structure to reduce the gate-to-source overlap capacitance (Cgs). A 40% reduction in Cgs is achieved when compared to conventional UMOS. A specific on-resistance Ron, sp = 60m2·mm2 is observed, which is 45% better than that of the conventional UMOS. The improvement in the device’s Figure-of-Merit (FOM = Ron × Qg) is about 58%.
A floating RESURF EDMOS (BV=55V, Ron,sp=36.5m2·mm2) with a 400% improvement in the Safe Operating Area (SOA) when compared to the conventional EDMOS structure is also presented. The proposed EDMOS employs both drain and iii source engineering to enhance SOA, not only via reducing the base resistance of the
parasitic bipolar transistor, but also suppressing the base current of the parasitic bipolar transistor under high Vgs and high Vds conditions. A buried deep Nwell allows the device to have better trade-off between breakdown voltage and on-resistance.
Finally, in order to achieve low gate charge in the EDMOS, a novel orthogonal gate
electrode is proposed to reduce the gate-to-drain overlap capacitance (Cgd). The
orthogonal gate has both horizontal and vertical sections for gate control. This device is implemented in a 0.18?m 30V HV-CMOS process. Compared to a conventional EDMOS with the same voltage and size, a 75% Cgd reduction is observed. The FOM is improved by 53%.
27
Sun, Hai-Tow y 孫海濤. "Electrical Characteristics of PANI/TiO2 Nanocomposites". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/81799824853723595677.
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碩士中原大學
應用物理研究所
95
Abstract In this thesis electrical characteristics of polyaniline (PANI)/photocatalyst TiO2 nanocomposites are studied. We measured sample ingots by direct current from 10 V to -10 V to study the electrical characteristics of PANI/TiO2 nanocomposites. After annealing process, the conductivity of the sample is promoted obviously in the temperature range from 20 K to 300 K. When the annealing temperature is over 573 K, the conductivity of the sample starts to decrease. In this case we quote the model of Mott variable range hopping (VRH) and space charge limited conduction (SCLC) to explain the electron transport behavior of the sample. In the result of scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) analysis, we believe that PANI starts to melt at 473 K and becomes carbonizated completely over 643 K. Furthermore, We find that PANI doped with TiO2 may improve the sample photoluminescence (PL) efficiency by spectroscopy analysis.
28
張立武. "The Electrical Characteristics of Planar Inductors". Thesis, 2004. http://ndltd.ncl.edu.tw/handle/09861116766245981196.
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碩士義守大學
電子工程學系
92
Microstrip, with low cost and easier fabrication, was adopted as planar inductors in the microwave circuits. In this work, planar inductors were divided into two categories: spiral inductors and meander inductors. A spiral inductor is one-port type, whereas meander one is a two-port inductor. The simulator IE3D was adopted to simulate the electrical properties of inductors. The effects of the line width, line pitch, and number of turns on the inductance and quality factor of the inductors were investigated. The simulated results were compared with those of the measured ones. The measured inductance approximates that of the simulated ones. There is a little deviation of quality factor between the measured and simulated results in low frequency range. The quality factor of measured inductors approximates that of the simulated one in high frequency range. We focus on the establishment of an equivalent circuit model for meander inductors. Each parameter of the equivalent circuit model was calculated. Both the Serenade SV8.5 and IE3D simulators were employed to simulate the response of the meander inductors. The measured results were also compared with those of the simulated ones. The measured results were found to be in close agreement with those of the simulated results by IE3D or SV8.5. The proposed equivalent circuit model can predict the frequency response of the meander inductors.
29
Chang, Yu-Hao y 張祐豪. "Electrical Characteristics of PANI/Au Nanocomposites". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/zjjcuj.
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碩士中原大學
物理研究所
102
Abstract This study aims to the electrical properties of the composite material mixed by Polyaniline (PANI) and gold nanoparticles. We used two kinds of PANI which were doped or dedoped with proton acid. These two different PANI samples were mixed with gold nanoparticles of which particle size is about 20 nm. After mixed uniformly in liquid phase, the samples were dried and pressed into pellets for electrical analysis. The concentration of gold nanoparticles and their particle size were confirmed by ultraviolet–visible absorption spectroscopy (UV-Vis) and scanning electron microscope (SEM). The composition of PANI power was analyzed by thermal gravimetric analyzer (TGA). Atomic force microscopy (AFM) was used to check the morphology of the samples annealed at different temperatures. Finally, two different types of composite materials including different amount of gold nanoparticles were proceeded to electrical analysis. The four-point measurement and impedance analyzer (LCR) were used in the analysis. The difference of their DC conductivity was measured and discussed. On the other hand, the AC measurement at different frequencies was proceeded to get the following five parameters: (1) AC conductivity (2) the real part of the effective relative complex permittivity (3) the imaginary part of the effective relative complex permittivity (4) capacitance (5) dielectric loss. The performance differences of the two composites were compared and discussed.
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Li, Hung-Wei y 李泓緯. "Study on Electrical Characteristics and Physical". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/51023890582627107516.
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博士國立交通大學
光電工程學系
100
In order to investigate the mechanism of photo leakage current of poly-Si TFT, the poly-Si TFTs with patterned metal shielding layer are used to study. The location of the exposed region in poly-Si layer is defined by employing the proposed structure. The exposed region’s photo leakage current increased at the drain junction location; therefore, the drain junction was the effective area in inducing photo leakage current under light exposure. The drain-exposed poly-Si TFT exhibits a significantly high photo leakage current and a slight subthreshold swing degradation under illumination. However, the exposed region located at the source junction significantly degraded at the sub-threshold swing of TFT under illumination with an increase in drain bias. In other words, the accumulated holes will, however, affect the applied gate voltage at the source junction and cause the degradation of the S.S. in the poly-Si TFTs under illumination. Besides, the analytical model was applied to extract the parameters. Based on the experimental results and analytical parameters, a band diagram was proposed to explain the degradation of subthreshold swing. Next, the interface treatment is applied at the bottom interface surface between poly-Si film and top buffer layer in the poly-Si TFTs. The NH3 is used to serve as the treatment gas. In order to verify the proposed method, the Ar ion implant is also used to treat the interface. From experimental results of the Ar ion implantation device, the maximum degradation of sub-threshold is 46.4% and the photo leakage current is about 8.6pA under the 5620nit back-light illumination. However, the photo leakage current of conventional device exposed to the 2160 back-light brightness was about 13.6pA. By introducing the trap states, the excess electron-hole pairs would have probability to recombine at the defect sites to decrease the photo leakage current and moderate the degradation of sub-threshold swing. Besides the Ar ion implantation is used to treat the interface, the NH3 gas plasma also can be applied at the interface to create defect states. However, the channel doping is usually applied for modulate the threshold of poly-Si TFTs. In this study, the photo leakage current of poly-Si TFT with channel doping modulation is also investigated. By adjusting the implantation energy, the target depth of the implantation set at the interface. The device with the channel doping modulation has the best result of the photo leakage current. Third, the stability of poly-Si TFTs under both darkened and backlight illumination environments is investigated. The stability tests include DC hot-carrier stress and dynamic AC stress. In the DC hot-carrier stress, the experimental results showed the ON-current degradation under the backlight illumination was slightly higher than the darkened environment. The extra electron-hole pairs, generated by the back-light illumination, would influence the electric field near the drain junction and they would also reduce the channel-hot-carrier stress. Besides, the four terminal devices n-channel poly-Si TFT with counter-doped lateral body terminal was applied in order to monitor the hole current generated by the ionization impact near the drain junction. In the other part, both conventional and patterned metal-shielding structures are used to verify the reliability of the poly-Si TFTs under darkened and illuminated dynamic AC stress. Experimental results indicate that during the illuminated stress the competitive mechanisms of carrier increase and electric field reduction are generated. Forth, the lateral body terminal Silicon-Oxide-Nitride-Oxide-Silicon Thin-Film-Transistors (LBT SONOS TFTs) is proposed to enhance the erasing efficiency. This device has superior erasing efficiency by gate as well as lateral body electrode exerting bias. The erasing mechanism of LBT SONOS TFTs has been illustrated by the energy band diagrams. Holes gain sufficient energy by electric field in deep depletion region to surmount the tunneling oxide barrier because of exerting body bias under erasing operation. Also, the lateral body terminal exerting bias can enhance erasing efficiency and which is confirmed by different erasing conditions and structure. In addition, to verify the hole current injecting from the lateral body site, the size effect of LBT SONOS TFTs is also discussed. In addition, the hump phenomenon presents at large width of the LBT SONOS TFTs after erasing operation has also been discussed and explained it with the schematic diagram. Besides, the fabrication of SONOS-TFTs with lateral body terminal is quite easy and involves no additional processes. Such a SONOS-TFT is thereby highly promising for the future system-on-panel display applications. Fifth, the sol-gel spin-coating method is used to fabricate the Zr or Sn doped zinc oxide based thin film transistor. Regardless of the deposition method, all undoped ZnO conducting films have unstable electric properties in the long term. This stability is related to the change in surface conductance of ZnO films under oxygen chemisorptions and desorption. The gas ambient effect on the photo leakage current、the electrical characteristic of bias temperature、gate bias stability and hysteresis of transfer characteristics would be investigated. Last, a brief review of the mechanism of chemisorbed and physically adsorption would be discussed. Based on the mechanism and the above experimental results, a new method would be proposed to remove the chemisorbed and physically adsorbed of oxygen. In the proposed method, the light, heat, and vacuum environment were employed simultaneously. This proposed method is based on that the photo generated holes could easily migrate to the chemisorptions site due to the built-in electric filed and transition from chemisorbed state to a physisorbed state. The heat is used to overcome the van der waal force. Besides, the environment should in a vacuum environment to ensure that the desorbed oxygen could be evacuate from the chamber. By applying the proposed on the ZnO-based devices, the stability of the ZnO-based devices were greatly improved. Furthermore, these results can be as important information for the subsequent passivation process concerning the pre-treatment of the active layer.
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Lin, Yi-Chun y 林怡君. "Electrical characteristics of dent-gated MOSFET". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/17768790961177210394.
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HUANG, SHU-XIANG y 黃姝香. "Electrical characteristics of the tantalum oxide". Thesis, 1986. http://ndltd.ncl.edu.tw/handle/23371696837786450302.
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Lin, Yu-Sen y 林宇森. "Electrical Characteristics of Bend Discontinuity andCompensation Design". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/15449150702199613060.
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碩士臺灣大學
電機工程學研究所
95
As the data rates increase into the multi-gigabit range, the effect of bend discontinuities on printed circuit board becomes non-negligible. this paper utilizes the commercial electromagnetic field solver to extract Z-parameters of the bend discontinuities. With the T-type equivalent circuit being extracted and verified, the waveform along bent transmission line in a high-speed digital circuit is simulated to demonstrate the signal integrity effect of the single bend. Because the differential signaling has the property of low noise generation and the high immunity to common-mode noise, it has become a popular option for multi-gigabit digital applications. The signal integrity analyses for bent differential transmission lines in a high-speed digital circuit are therefore performed in the time domain. One practical compensation scheme, the dual back-to-back bends, for the common-mode noise reduction are further investigated. To alleviate the common-mode noise at the receiver, a novel compensation scheme in use of the bump delay line is also proposed. However, the most important contribution in this thesis is to provide the complete flows of designing bump delay lines so that the designer could follow the steps of the proposed method to design a perfect and practical bump while both keeping good SI and using least layout space. Finally, the comparison between the simulation and measured results validates the analysis approach of differential bends with the proposed bump delay lines.
34
Lee, Min-Jae. "Normal project performance characteristics for electrical costruction". 2000. http://catalog.hathitrust.org/api/volumes/oclc/48624689.html.
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Thesis (M.S.)--University of Wisconsin--Madison, 2000.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 96-98).
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Hsu, Yao-Sheng y 許耀升. "Characteristics and electrical properties of ZnO nanorods". Thesis, 2019. http://ndltd.ncl.edu.tw/cgi-bin/gs32/gsweb.cgi/login?o=dnclcdr&s=id=%22107NCHU5198015%22.&searchmode=basic.
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碩士國立中興大學
物理學系所
107
This study will investigate the electrical transport properties of ZnO nanorods as transistors and the use of ionic liquid as gate. In the experiment, the surface of uniform ZnO nanorods was prepared by Hydrothermal method, and the ZnO nanorods was annealed at different temperatures using Rapid Thermal Annealer. Subsequently, Scanning Electron Microscope (SEM), Photoluminescence (PL), Raman and X-ray diffraction (XRD) were used to observe the surface morphology, structural defects and crystal orientation of samples and select samples with good quality for annealing temperature. We chose the annealing 500 °C of ZnO samples and Au/Ti electrodes are changed with the temperature after the electrical measurement, observe ZnO materials and contact between the metal electrode, as well as the analysis of ZnO nanorods of thermal activation energy and electron transport, and through the Low Frequency Noise measurement to check the stability of the sample. Combined with the above conclusions, we find that annealing at 500 °C is suitable for ZnO nanorods growth, that the Contact between ZnO semiconductor material and metal electrode is Ohmic Contact and discusses the zinc oxide in different temperature area electronic transmission mode of Thermal Activation Transport and Variable Range Hopping. In addition, we use ionic liquid as the gate pole. On the one hand, we measure the switching properties of the transistor itself and verify that our ZnO is n-type semiconductor; on the other hand, we use it as the logic circuit and use the element as inverter to detect the performance test on the logic element. Based on the above applications, we found the potential of ZnO nanorods as electronic components.
36
Eshiemogie, Ojo Evans. "Dynamic characteristics of bare conductors". Thesis, 2011. http://hdl.handle.net/10413/5826.
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The dynamic characteristic of transmission line conductors is very important in designing and
constructing a new line or upgrading an existing one. This concept is an impediment to line
design and construction because it normally determines the tension at which the line is strung
and this in respect affects the tower height and the span length. Investigations into the
phenomenon of mechanical oscillation of power line conductors have been extensively looked
into by many researchers using concepts from mechanics and aerodynamics to try and predict the
conductor dynamic behaviour. Findings have shown that precise prediction of conductor windinduced
vibration is very difficult i.e. non-linearity.
Over the years, various analytical models have been developed by researchers to try and predict
the mechanical vibration of transmission line conductors. The first part of this dissertation
considers the analysis of the model describing the transverse vibration of a conductor as a long,
slender, simply supported beam, isotropic in nature and subjected to a concentrated force. The
solution of this beam equation was used to obtain the conductor natural frequencies and mode
shapes. Conductor self-damping was obtained by the introduction of both external and internal
damping models into the equation of motion for the beam.
Next, also using the same beam concept was the application of the finite element method (FEM)
for the dynamic analysis of transmission line conductors. A finite element formulation was done
to present a weak form of the problem; Galerkin‟s method was then applied to derive the
governing equations for the finite element. Assembly of these finite element equations, the
equation of motion for the transverse vibration of the conductor is obtained. A one dimensional
finite element simulation was done using ABAQUS software to simulate its transverse
displacement. The eigenvalues and natural frequencies for the conductors were calculated at
three different tensions for two different conductors. The damping behaviour of the conductors
was evaluated using the proportional damping (Rayleigh damping) model. The results obtained
were then compared with the results from the analytical model and the comparison showed a
very good agreement.
An electrical equivalent for the conductor was developed based on the concept of mechanicalelectrical
analogy, using the discrete simply supported beam model. The developed electrical
equivalent circuit was then used to formulate the transfer function for the conductor. Matlab
software was used to simulate the free response of the developed transfer function.
Finally, the experimental study was conducted to validate both the analytical model and the
FEM. Tests were done on a single span conductor using two testing methods i.e. free and force
vibration. The test results are valid only for Aeolian vibration. From the test results the
conductor‟s natural frequencies and damping were determined. The experimental results, as
compared with the analytical results were used to validate the finite element simulation results
obtained from the ABAQUS simulation.Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2011.
37
Kuo, Chun-Wen y 郭淳文. "Electrical Characteristics of Si/SiGe/Si Tunneling Structure". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/94477093982102166911.
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碩士國立高雄應用科技大學
電子與資訊工程研究所碩士班
91
An ultra-thin base Si/SiGe/Si heterojuction bipolar transistor (HBT) is theoretically investigated. In such a structure, many advantages of conventional HBT, such as high current gain and high emitter efficiency etc., are reserved, and a small recombination rate and high cutoff frequency are achieved by shortened the base width. In this study, we find the quantum tunneling effect predominates the carrier transport, when the base width is tuned as less than the mean-free-path of materials and comparable with the de Broglie wavelength of carriers. In this situation, Boltzmann transport no more plays the role, instead, the coherent tunneling or quantum Boltzmann transport dominates the electrical property of the device. From our analysis, the collector current shows a novel feature of resonant attributed to the transition from single-barrier tunnel structure to quantum-well structure. It is a testable feature for the transition from classical transport to quantum transport.
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Kuo, P. S. y 郭培烜. "Electrical and optical characteristics of GaAs/GaAs0.982N0.018/GaAs". Thesis, 2000. http://ndltd.ncl.edu.tw/handle/05229793126280734125.
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碩士國立交通大學
電子物理系
88
The hetrostructure of GaAsN/GaAs quantum well has a relatively large condouction-band offset and is a suitable material for long-wavelength laser diodes（lasing at 1.3~1.5μm or longer wavelengths）. However when well thickness increase beyond the critical thickness， lattice relaxation occurrs and the carrier depletion around the quantum well is observed . The photoluminescence reveals a strong blueshift of GaAs0.982N0.018/GaAs quantum emission . The X-ray rocking curve show that the critical thickness of GaAs0.982N0.018/GaAs single quantum well is around 175A~295A . Based on the concerntration profile ，we obtain that the conduction-band offset ΔEc of GaAs0.982N0.018/GaAs single quantum well is around 0.28eV and the ΔEv is around 50meV . The band diagram of GaAs0.982N0.018/GaAs single quantum well is shown to be Type-II . Three deep levels（active energy 0.51、0.44~0.48 and 0.16eV） are observed by DLTS in relaxed samples .
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Chian, Wei-Ning y 錢韋寧. "Electrical Characteristics of Via Discontinuity and Compensation Design". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/36287955220664886702.
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碩士國立臺灣大學
電信工程學研究所
95
In the multilayer printed circuit boards (PCBs), the through-hole via transitions are always utilized to link the signal traces between different layers. As the data rates increase up to several GHz, it is essential to consider the significant impact of vias on signal integrity of high-speed digital systems. Usually, it is found to be capacitive and would cause a voltage drop in the time-domain reflectometry (TDR) waveform. To reduce this reflection noise, this thesis describes a systematic design procedure to improve the electrical performance of multilayer through-hole via transitions by using the high-impedance interconnects. In addition to the thinner transmission line, a novel matching structure is proposed by changing the anti-pad shape from circular to capsular to achieve the better broadband matching condition. The compensation method also applies to a differential via transition successfully. To make the design of compensation more complete, a way of combining two compensation methods applies to the via stub structures. This method is demonstrated by the time-domain simulation and measurements, accordingly.
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Chien, Jui-Cheng y 簡瑞成. "Electrical characteristics of gate-controlled nanowire Schottky diodes". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/25kgn9.
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碩士國立交通大學
材料科學與工程學系奈米科技碩博士班
104
In recent years, multiple gate structure field effect transistor and Schottky diode have been widely studied in order to boost the electrical abilities of the semiconductor devices for low-power applications. As a result of high surface-to-volume ratio, the scaling of the channel of modern electronic device to nanometer size enhances the sensitivity of electronic device to the gate voltage. In this thesis, we fabricated silicon nanowire with 3553 nm cross-section via I-line and side wall spacer technique. The nanowire was then wrapped with trigate structure. After the formation of gate, nickel silicidation was performed along the channel of silicon nanowire to form a metal-semiconductor junction under the gate. Material characterizations of this gate-controlled Schottky diode were performed by SEM, TEM and EDS. The discussion of carrier transport behaviors under the gate biases is also included. The Electrical characteristics of the gate-controlled Schottky diode exhibits that both 400 mV and 50 mV gate bias induce effective current changes at the reverse bias. The limitation of gate bias sensitivity is about 10 mV. If the defects at gate/channel interface can be further minimized, the Schottky diode can be a sensitive device to gate potential change
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Shen, Chi-Ling y 沈志領. "Electrical characteristics of GeSn p-i-n structure". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/k9pe5r.
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碩士國立臺灣大學
電子工程學研究所
105
In recent years, GeSn-based p-i-n diodes have attracted great research attention on group IV opto-electronics such as photodetectors and emitters operated at near infrared wavelengths. Lots of efforts have been done to obtain the photo-electronic properties such as light absorption or emission. However, to further understand the electrical characteristics is needed. For optical receivers the critical photodiode parameters are dark current, responsivity, and bandwidth. In this paper, we will focus on dark current which may increase the power consumption and degrade the signal-to-noise-ratio (SNR) of the integrated optical receivers. However, for a practical GeSn-based diode, the I-V analysis is complicated, for example, the potential barriers at the hetero-interface as well as at the metal/semiconductor contact. Therefore, deeper investigation on the carrier transport and behaviors is needed. In this paper, we will report on two different GeSn-based p-i-n diodes, N924 and N935, which fabricated by MBE, then briefly analysis the result of electrical characteristics from our measurements.
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Cheng, Han-Wen y 鄭涵文. "Dependence of Electrical Characteristics on MoS2 Synthesis Method". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/y447cp.
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碩士國立交通大學
材料科學與工程學系奈米科技碩博士班
107
In this thesis, molybdenum disulfide (MoS2) materials with different preparation methods will be discussed. After different process treatments, we choose two types of metal Mo and Ni/Au which are used to fabricate the contact metal pad and compared the electrical effects of these process. In recent years, many studies have used exfoliation to fabricate molybdenum disulfide devices and developing many research methods to improve the electrical properties of MoS2 devices. Although this preparation way is extremely quick, convenient and the process is simple, but the MoS2 film area is very tiny and the material thickness is not uniform. Above characteristics make it difficult to apply on the industrial chain of mass production. Therefore, this work will use the recently popular molybdenum disulfide material synthesis method- chemical vapor deposition (CVD) and another two-step MoS2 synthesis method to make electrical comparisons, we will separate two parts to carry out: (1) 2-step method MoS2 device was subjected to an induce couple plasma (ICP) pretreatment and an annealing process, respectively. (2) CVD MoS2 FET is covered SiO2 capping layer on channel and executed annealing process. It is desirable to improve the sheet resistivity (rSH) and contact resistance (RC) of the MoS2 device. The results show that the 2-step method MoS2 device has a very high rSH and RC values after ICP pretreatment and high temperature annealing, which is close to the insulator state due to high defect density. The capping layer of the CVD MoS2 FET improves the ID-VG electrical properties of the device. There is also improved electrical performance after annealing at 300 °C. From the above experimental results, we can summarize that in the initial process step, we need to choose a MoS2 material with high quality, low defect and low rSH. And avoiding the degradation of MoS2 material by environment and process in the subsequent process. It is the most essential procedure in manufacture a good electrical MoS2 devices.
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Yang, Ysung-Yu y 楊宗祐. "Influence of Drain Electric Field on Electrical Characteristics in Poly-Si Nanowire Thin Film Transistors". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/02000394408552716689.
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碩士逢甲大學
電子工程所
100
Poly-Si thin-film transistors (TFTs) have been widely used as switching elements in active matrix display. For applications on system-on-panel (SOP) and three-dimensional integrated circuits (3-D ICs),further improvements of device performance and reduction of the device size are required. When the device size is reduced, there are some short channel effects which are the development of a choke point. Recently, the tri-gated poly-Si TFT with multiple nanowire channels (MNC) was proposed. The tri-gated MNC TFT exhibits excellent electrical performance as compared to conventional planar (CP) TFT, because it has better gate controllability and the ratio of surface area to volume. However, the tri-gated MNC TFTs has the problem of offset leakage current, because there is a high electric field at the sharp corner. Moreover, there is a kink effect when operated at a high drain voltage. By T-gate and inside nitride spacer structures, the drain electric field can be reduced, which can be simulated by ISE-TCAD software. The measured results show that the leakage current and kink effect are significantly improved for the proposed TFTs. Therefore, the nanowrie channel TFTs with T-gate structure and inside nitride spacer designs are feasible for the SOPs and 3-D ICs.
44
Chen, Jing. "Electrical and switching characteristics of lithium niobate thin films". Thesis, 1996. http://hdl.handle.net/1911/14058.
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C-V and I-V measurements combined with pulse application were employed to study the electrical characteristics of lithium niobate thin film samples. Though the C-V measurements showed some classical features, a lithium drifted n-i-p junction model was postulated to explain the low nominal dielectric constant in C-V characteristics. The I-V characteristics were analyzed and the field dependence was determined to be Frenkel-Poole emission at low field and possibly Fowler-Nordheim at high field.
A four-pulse dual-polarity pulse train was then used to study the switching kinetics of these thin films. The resulting transient current was captured and unstable switching was found in some samples. The polarization reversal was found to be dominated by forward domain growth with virtually no sideways motion. Finally, some important time constants such as nucleation time and domain wall growth time were determined and analyzed.
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Hsu, Chung-Yi y 徐崇益. "Opto-Electrical Characteristics of Alq3 Deposited by Thermal Evaporation". Thesis, 2003. http://ndltd.ncl.edu.tw/handle/80945542558020080418.
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碩士國立成功大學
化學系碩博士班
91
Photoluminescence quenching of Alq3 [Tris ( 8-hydroxy quinoline ) aluminum (Ⅲ)] is seriously affected by many parameters including substrate material, layer thickness, storage time, and humidity et al. In this study, we have demonstrated device performance affected by film uniformity, atomic arrangement, material characteristics, and evaporation parameters. The optimal evaporation rate is 2 Å/s, and substrate heated at 60°C for 20 min when interface between deposited layers, and the thickness of NPB layer and Alq3 layer in the single hetero-junction device are 400 Å and 300 Å respectively.
46
Li, Chen-Yi y 李宸毅. "Study of the Characteristics of Electrical Signals in Plants". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/38402333963674161898.
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碩士國立宜蘭大學
生物機電工程學系碩士班
98
Electrical signals have emerged as a subject of recent interest in plant physiological research, and two major types of electrical signals, action potential and variation potential, have been identified in plants. Action potential （AP） is a fast electrical pulse that has well-defined properties. Variation potential （VP） is not well defined in many aspects such as waveform, amplitude, polarity, and conduction velocity, and its generation is subject to different mechanisms. Chemical and hydraulic mechanisms are two candidates in the literature and have been studied in wounded plants. In this study, two novel methods were designed to investigate the mechanism of variation potential, including a method for blocking electrical signal transmission and a method for measuring hydraulic variation. The former method used the proton pump （H+/K+ ATPase） inhibitor, NH4Cl, to block electrical signal transmission while the control inhibitor （water） cannot block the transmission. The hydraulic change was measured by the latter method for heat-wounding tomato plants. Results showed that heat wound evoked both hydraulic pulse and VP in tomato plants; the transmission of VP was blocked by the inhibitor （NH4Cl） while the hydraulic pulse was not, indicating that VP was not induced by hydraulic variation. In addition, the hydraulic pulse preceded VP following the heat wound. We conclude that the wound-induced VP is not generated due to hydraulic variation but chemical mechanism.
47
Lee, Kayoung. "Electrical characteristics of Bernal stacked (A-B) graphene bilayer". 2012. http://hdl.handle.net/2152/19043.
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Graphene bilayers in Bernal stacking exhibit a transverse electric (E) field dependent band gap, thanks to the on-site electron energy asymmetry between the two layers, which can be used to increase the channel resistivity, and enable higher on/off ratio devices. Using dual-gated device structure, we investigate the transport characteristics of exfoliated graphene bilayers as a function of carrier density and E-field at temperature from 295 K down to 0.3 K. At high E-field, strong conduction suppression near the charge neutrality point is observed, a primary characteristic introduced by band gap opening. The conductivity suppression persists up to the finite threshold voltages, which increase with increasing the E-field, similar to a gapped semiconductor. We extract the transport gap as a function of E-field from the threshold measurement, and further discuss the impact of disorder. At gate bias higher than the threshold, conductivity increases linearly as carrier density increases, which contrasts to the sub-linear dependence in graphene monolayer. Mobility shows decreasing tendency with the increasing E-field, which changes little as temperature changes. Besides, we probe the electrical characteristics of quasi-free-standing graphene bilayers grown on SiC at temperature down to 0.3 K, based on the study on the exfoliated graphene bilayers. The epitaxial graphene bilayer on SiC is prepared by atmospheric pressure graphitization in Ar, followed by H₂ intercalation, which renders the material quasi-free-standing. At the charge neutrality point, the longitudinal resistance shows an insulating behavior, and follows a temperature dependence consistent with variable range hopping transport in a gapped state. Besides, clear linear dependence of the conductivity on the carrier density is observed, which is distinguishable from the sub-linear dependence in graphene monolayer. These properties show that the epitaxial graphene bilayer grown on the SiC exhibits band-gap opening and Bernal stacked arrangement.text
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Her, Qiu-Kuan y 邱寬和. "Micro Electrical Discharge Machining Characteristics of Nikel-Molybdenum Alloy". Thesis, 2002. http://ndltd.ncl.edu.tw/handle/46611279175519797439.
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Hung, Li-Yue y 洪藜月. "Measurement and Simulation on Electrical Characteristics of Electronic Packages". Thesis, 2001. http://ndltd.ncl.edu.tw/handle/13118723505687454429.
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碩士國立雲林科技大學
電子與資訊工程研究所碩士班
89
As high-speed computers and wireless communications systems have accomplished a remarkable development in recent years, the clock speed in many integrated circuits reaches hundreds megahertz or tens gigahertz. At such a high frequency, the rise time of the signal is relatively shortened. As a result, electrical parasitic effects on the packages will significantly degrade the sequential timing and noise performances on digital logic circuits. Therefore, it is an important task to establish the equivalent models for electrical characteristics on packages and to analyze the signal integrity of high-speed digital signals. The research objective in this thesis focuses on mBGA (mini Ball Grid Array). Full two-port scattering parameter was measured on devices under test with a vector network analyzer. The measurement standard from HP GigaTest Labs was adopted for measurement of frequency domain response on scattering parameters. In addition, the HP ADS (Advanced Design System) software was employed to establish the lumped and discrete models for package conductor wires. With the optimization capability of the ADS, electrical model was established with satisfactory accuracy. The validity of the model was confirmed by a comparison between scattering parameters from ADS simulation and from measurement. In respect of the electromagnetic simulation, in order to verify the equivalent circuit model for the package wires, the Ansoft Maxwell quick 3D Parameter Extractor software was used to calculate the inductance and capacitor matrices. Finally, HSPICE was applied to analyze the signal integrity of the conduction wires in the package.
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LIU, Hong Song y 劉弘松. "Characteristics of Titanium Alloy in Microenergy Electrical Dischage Machining". Thesis, 1993. http://ndltd.ncl.edu.tw/handle/92305571491538431789.
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碩士國立中央大學
機械工程研究所
81
Owing to the high corossion resistance,high temperature resistance, and high specific strength, titanium alloy is used widely in aerospace industry. This experiment adapts the most applied Ti-6Al-4V in aerospace industry as the experiment- tal material and electrode in electrolyzed copper to discuss the characteristics of titanium alloy in microenergy electrical dischage machining . The experiments of microenergy electrical dischage are carried out with the methods of dielectric suspended unconductive electric powder and without powder, and the spindle orbiting or fixed. It mainly discuss the characteristics of micro energy machining such as surface roughness of workpiece,relative electrode wear ratio, and material removal rate to set up the complete microenergy machining conditions of Ti-6Al-4V to provide the industry as reference. From the results of the experiment, e machining methods getting the glossy surface is to adapt negative polarity of copper electrode, add no powder inelectric, set up the small discharge current and pulse duration , and use the orbiting head device at the same time.