- 标题
- 摘要
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- 实验方案
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Sol-Gel Derived Dip Coated ZnO – La <sub/>2</sub> O <sub/>3</sub> Thin Film Transistors
摘要： ZnO thin ?lms are fabricated utilizing a cost effective sol-gel dip coating technique and potentially applied as active material in thin ?lm transistors (TFT). The channel length of the TFT is maintained at 40 μm. Thermally deposited high –k La2O3 is used as dielectric material. The fabricated ZnO ?lms are annealed in oxygen atmosphere at 500?C for 1 hour and characterized by XRD, EDX and SEM analysis. The TFTs are fabricated in top gate coplanar electrodes structure on glass substrates. The electrical characteristics of the TFTs are investigated and some important electrical parameters are evaluated. The TFTs exhibit ?eld effect mobility of 1.9 cm2/VS, low threshold voltage of 2.5 Volt, high ON/OFF current ratio of 107, sub-threshold swing of 0.8V/decade, transconductace of 1.2 × 10?3 mho and gain band-width product of 20 kHz.
关键词： ZnO,sol-gel dip coating,thin film transistors,electrical characteristics,La2O3
更新于2025-09-11 14:15:04
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<b>Impact of modified perturb and observe control on MPPT of PV/battery fed three - port DC‐DC converter
摘要： This paper presents the modified perturb and observe (P&O) maximum power point tracking (MPPT) method for photovoltaic (PV) fed three-port DC‐DC converter in PV/battery hybrid system. The proposed MPPT technique reduces the drift problem which occurs in the conventional MPPT methods by including the data of change in current (ΔI) in addition to the data used in the conventional P&O algorithm. The drift phenomenon and its effects are clearly demonstrated in this paper. The ability of the proposed P&O method to address this issue is proved by comparing the conventional P&O algorithm in different modes of operation. The performance assessment includes peak overshoot, settling time, MPP ratio and stability. The experimental validation was implemented using DSPIC30F4011 microcontroller. From the analysis and results, it could be seen that the modified P&O showed better performance in terms of accuracy in tracking the maximum power, less tracking time, high MPP ratio and reduced drift in the changing weather conditions.
关键词： DC‐DC power converters,current-voltage characteristics,photovoltaic systems,drift,power demand,pulse width modulation
更新于2025-09-10 09:29:36
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Diagnostic method of solar thermal system based on the short time on-line measurements
摘要： This paper presents the method of a solar heating system diagnostics allowing determination of the following coefficients in operating conditions: heat loss coefficient ULK, collector efficiency factor F’ and heat removal factor FR related to the collector static properties, effective heat capacity (mc)e and time-constant Tz related to the collector dynamic properties. The proposed method is based on a comparison of two models: analytical and numerical. The analytical model was developed based on the collector energy balance and that combining characteristic parameters. The numerical model was developed based on the recorded operating data of the medium inlet and outlet temperature, and solar irradiance. The condition necessary to apply this method covers constant volume flow rate of the medium in the system during the experiment.
关键词： time-constant,parametric identification,solar collector,efficiency characteristics
更新于2025-09-10 09:29:36
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[Micro/Nano Technologies] Micro and Nano Fabrication Technology Volume 1 || Fabrication of Metallic Nanodot Arrays
摘要： Metal nanodot arrays exhibit unique optical characteristics, and they are expected to find widespread applications in biosensors and various optical devices. In this section, simple and efficient manufacturing processes are introduced for metal nanodot arrays. These processes are based on the combination of thin metal film coatings deposited on substrates and thermal dewetting. The first process discussed herein is a conventional thermal dewetting method. With this method, it is shown that the average dot diameter can be controlled based on the chosen process conditions. The second process is based on the use of grid patterning on coated metal films. This process can allow fabrication of nanodot arrays with uniform dot diameters and achieve highly ordered alignment of dots. The third process generates a metal nanodot array based on a self-organization manner on a nanogrid-patterned substrate. It constitutes a high-productivity process based on the transfer of the metal nanodot array to an adhesive film. The basic mechanisms underlying these processes are discussed herein.
关键词： Productivity,Metal coating,Dot transfer,Surface energy,Metal nanoparticles,Agglomeration,Nano plastic forming,Optical characteristics,Grid patterning,Self-organization,Biosensors,Thermal dewetting
更新于2025-09-10 09:29:36
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Application of the Method of Moments for Calculating Electrodynamic Characteristics of a Quasistatic Antenna in an Anisotropic Medium
摘要： We develop the numerical method of moments for solving an integral equation that describes the distribution of the charge along a thin finite-length antenna wire in an anisotropic medium in the quasistatic approximation. It is shown that the method of moments can be used to calculate the electrodynamic characteristics of such an antenna under the conditions where the kernel of the integral equation has a singularity related to the resonance cone. The influence of the ratio between the elements of the dielectric permittivity tensor and the method of partitioning of the antenna surface on the calculation accuracy is analyzed. It is shown that the relative error of calculations of the antenna characteristics is a fairly small value of about 1 % if the antenna wire is divided into ten segments.
关键词： electrodynamic characteristics,anisotropic medium,resonance cone,method of moments,quasistatic antenna
更新于2025-09-10 09:29:36
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crystal structure on the stability of polymer composites exposed to vacuum ultraviolet radiation
摘要： Vacuum ultraviolet (VUV) radiation produced by the Sun in the space environment can cause degradation to thermoregulating coatings producing changes in optical, mechanical, and chemical properties. These effects are particularly important for polymers. The purpose of this study was to study the effect of VUV radiation on polymeric composites based on polyalkaneimide. Amorphous and crystalline SiO2 were used as the filler. A comparative characterization of physico-mechanical properties of composites is presented depending on the polymorphic structure of the filler being introduced. According to the microhardness of the surface of composites with amorphous and crystalline SiO2, an optimum filler content of 60–65 wt% is established. The exposure of VUV radiation to polymeric composites with SiO2 leads to a mass loss and a change in their near-surface layers, which leads to a deterioration in the optical properties. At an elevated temperature (125oC), the mass loss of all composites with amorphous crystalline SiO2 does not exceed 1.33%, and with crystalline SiO2, the maximum mass loss is 0.52%. The mass loss of composites with crystalline SiO2 of all compositions did not exceed the allowable value for spacecraft products of 1%. For high-filled (50 wt% filler or more) composites with amorphous SiO2, mass loss after VUV treatment is more than 1%, which does not allow them to be used in outer space. The change in the main optical characteristics of thermoregulating coatings after VUV treatment was studied. The smoothing of the surface of composites after VUV treatment is established.
关键词： Spacecraft coverings,Deep vacuum,Optical characteristics,Gas evolution,Vacuum ultraviolet,Cosmic radiation
更新于2025-09-10 09:29:36
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Improving the Accuracy of Broad-Band Monitoring of Optical Coating Deposition
摘要： A method for improving the accuracy of the broad-band monitoring of the process of depositing optical coatings is proposed. The method is based on determining the actual set of thicknesses of deposited layers in the deposition process. The effectiveness of the proposed approach is demonstrated in a series of model numerical experiments using a simulator of deposition process.
关键词： spectral characteristics,broad-band optical monitoring,multilayer optical coatings
更新于2025-09-10 09:29:36
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The preparation and the photoelectric characteristics of graphene/MoSe <sub/>2</sub> heterojunction
摘要： The paper presents the preparation and optoelectronics characteristics of grapheme/molybdenum selenide (MoSe2) heterojunction.MoSe2 films was deposited on Si substratesusing used MoSe2 powder as a raw material by a chemical vapour deposition (CVD) method, and then the graphene/MoSe2 heterojunction was formed by grown a graphene layer on the MoSe2 film using methane (CH4) as a raw material. The prepared MoSe2 films were consisted of many nanowires about 2 nm in diameter and 7 nm in length perpendicular to the surface observed by an Atomic force microscopy (AFM), while many small graphene pieces were formed and dispersed on MoSe2film surface. Additionally, we found that the growth of MoSe2 film has a strong orientation growth in the (400) crystal plane, which consistent with the MoSe2 film composed of many parallel nanowires in the AFM picture. Moreover, we found that the graphene/MoSe2 heterojunction has good absorption properties for visible light and has a significant photocurrent generation under illumination, indicating that the graphene/MoSe2 heterojunction has excellent optical and electrical properties and has great potential for application in the field of optoelectronic devices.
关键词： MoSe2,graphene,CVD,photoelectric characteristics,heterojunction
更新于2025-09-10 09:29:36
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[IEEE 48th European Solid-State Device Research Conference (ESSDERC 2018) - Dresden (2018.9.3-2018.9.6)] 2018 48th European Solid-State Device Research Conference (ESSDERC) - Observation and Analysis of Bit-by-Bit Cell Current Variation During Data-Retention of TaO<inf>x</inf>-based ReRAM
摘要： This work analyzes the bit-by-bit memory cell current variation during the data-retention to study the long time data-retention behavior of TaOx-based resistive random access memory (ReRAM). For the first time, the current variation during data-retention is observed and analyzed for each memory cell of ReRAM. Cell current of low resistance state (LRS) cells shows complicated characteristics, that is, decreasing in the long term and fluctuating in the short term due to oxygen vacancy diffusion. On the other hand, high resistance state cell hardly shifts during the data-retention. A physical model for LRS cell current fluctuation is proposed in this study, based on the numerical calculation.
关键词： ReRAM,Data-retention characteristics
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Signal Modeling for Dynamic Testing of Smart Electricity Meter
摘要： By analyzing the typical large power dynamic loads characteristics, a general dynamic testing signal model and its three-phase m-sequence pseudorandom dynamic testing signal are established. Two kinds of smart electricity meters are measured, and the measurement uncertainty was evaluated. the results are given. Concurrently,
关键词： testing signal,dynamic load characteristics,measurement,m-sequence,smart electricity meter
更新于2025-09-10 09:29:36