铁电液晶空间光调制器氢化非晶硅薄膜 p—i—n光敏层的研究

描述了氢化非晶硅／铁电液晶空间光调制器的结构和工作原理，并从器件的电学模型出发，着重讨论了整体器件对光敏层的特性要求，对ａ－Ｓｉ：Ｈ薄膜ｐ－ｉ－ｎ光敏层的制作和光电特性进行了研究。     

层叠结构的Si0.65Ge0.35/Si红外探测器的微结构研究

采用定位的横断面透射电子显微术观察Ｐ＾＋－Ｓｉ０．６５Ｇｅ０．３５／ｐ－Ｓｉ异质结内光发射红外探测器的微结构。该器件光敏区由６层Ｐ＋－Ｓｉ０．６５Ｇｅ０．３６和５层ＵＤ－Ｓｉ层组成,每层都比较平整,各层厚度分别为６ｎｍ和３２ｎｍ,在Ｓｉ０．６５Ｇｅ０．３５／ＵＤ－Ｓｉ界面处存在应力场,但未到晶体缺陷,非晶ＳｉＯ２台阶上的Ｓｉ０．６５Ｇｅ０．３５和ＵＤ－Ｓｉ层是波浪状的多晶层,光敏区的边界处存在小于     

开路p－n结对近邻光电二极管特性的影响

对ｐ－ｎ结邻近有大面积受光开路ｐ－ｎ结的光电特性进行了理论和实验分析。结果表明，这种结构不能改善光敏器件的灵敏度和探测率，而且由于大面积受光开路ｐ－ｎ结的存在，器件的灵敏度和探测率比相同面的单个ｐ－ｎ结小。     

开路p－n结对近邻光电二极管特性的影响

对ｐ－ｎ结邻近有大面积受光开路ｐ－ｎ结的光电特性进行了理论和实验分析。结果表明，这种结构不能改善光敏器件的灵敏度和探测率，而且由于大面积受光开路ｐ－ｎ结的存在，器件的灵敏度和探测率比相同面的单个ｐ－ｎ结小。     

电力器件用的6H－SiC、3C－SiC和Si的比较

为了实现５０～５００Ｖ的击穿电压范围，本文详细讨论了６Ｈ－ＳｉＣ和３Ｃ－ＳｉＣ肖特基整流器和功率ＭＯＳＦＥＴ的漂移区性质。利用这些数值计算了器件的输出特性，并与Ｓｉ器件做了比较，结果表明，由于其漂移区电阻非常低，故５０００ＶＳｉＣ肖特基整流器和功率ＭＯＳＦＥＴ在室温下能够处理１００Ａｌｃｍ￣２的导通电流密度，正向压降仅分别为３．８５和２．９５Ｖ。这些数值甚至优于Ｓｉｐｉｎ整流器和门可关断晶闸管。这种ＳｉＣ器件由于没有少于结，故可期望有优良的开关特性和坚固耐用性。此外，还基于峰值结温极限是由封装考虑来确定的观点，报道了热学分析结果。应用这种分析发现，５０００Ｖ的６Ｈ－ＳｉＣ和３Ｃ－ＳｉＣＭＯＳＦＥＴ和肖特基整流器将比相应的Ｓｉ器件大约小２０和１８倍。对ＳｉＣ的热学分析表明，这些器件能在比常规Ｓｉ器件高的温度和击穿电压下工作。还有，在管芯尺寸上也期望有明显的减少，这将会补偿其材料成本较高的不足。本文报告的分析结果对ＳｉＣ功率器件的制造将会起到强大的推动作用。     

单片GaAs HBT p－i－n二极管可变增益放大器、衰减器和开关

单片ＧａＡｓ　ＨＢＴ　ｐ－ｉ－ｎ二极管可变增益放大器、衰减器和开关在ＧａＡｓＨＢＴ工艺中，人们可以用现有的材料层制作ｐ－ｉ－ｎ二极管，并可将其与ＨＢＴ集成在同一块单片上。ＨＢＴ器件结构的轻掺杂集电区层可用作ｐ－ｉ－ｎ的本征层；重掺杂基区和第二集电区可...     

红外探测器微结构的HREM观察

采用定位横断面制样的高分辨电子显微技术（ＨＲＥＭ）观察了Ｐ＋－Ｓｉ０．６５Ｇｅ０．３５／Ｐ－Ｓｉ异质结内光发射红外探测器的微结构．该器件光敏区是由３层Ｐ＋－Ｓｉ０．６５Ｇｅ０．３５和２层ＵＤ－Ｓｉ（未掺杂硅）组成,Ｓｉ０．６５Ｇｅ０．３５／ＵＤ－Ｓｉ层间界面不明锐,有一个由于Ｇｅ原子不均匀扩散造成的过渡带．这个过渡带缓和了界面的失配应力,因而未观察到界面晶体缺陷和严重的晶格畸变．在光敏区边缘有呈倒三角形的缺陷区,缺陷的主要类型为层错和微孪晶．层错在（１　１１）面上,而微孪晶的厚度约为２～４晶面间距,其孪晶     

P^＋—GexSi1—x／P—Si异质结内光发射（HIP）长波长红外探测器结构的…

本对Ｐ＾＋－ＧｅｘＳｉ１－ｘ／Ｐ－Ｓｉ异质结内光发射以长红探测器的电极结构进行了改进，并在国内首次报道了这种器件在７７Ｋ下的电学特性和光学响应特性。     

a－SiFET电流－电压特性研究

本文对ａ－ＳｉＦＥＴ的电流－电压特性的理论研究提出一种新的方法。其不需要引入ａ－Ｓｉ隙态密度分布的具体假设模型，采用合理的数学方法，推导出ａ－ＳｉＦＥＴ电流－电压关系的解析表达式，对ａ－ＳｉＦＥＴ电流－电压特性进行合理的解释。并且理论分析结果与实验结果能很好符合，为ａ－ＳｉＦＥＴ的理论分析开辟了一条新途径。     

高性能a-Si:H TFT开关器件的研制

介绍了ａ－Ｓｉ：ＨＴＦＴ开关器件的有源层、栅绝缘层、欧接触层以及界面特性的研究工作。研制了ａ－Ｓｉ：ＨＴＦＴ单管器件,其开关电流达到６个数量级,为最终研制ａ－Ｓｉ：ＨＴＦＴＡＭＬＣＤ在奠定了坚实的基础。     

High efficiency triple junction thin film silicon solar cells with optimized electrical structure

We report on improving the performance of pin‐type a‐Si:H/a‐SiGe:H/µc‐Si:H triple‐junction solar cells and corresponding single‐junction solar cells in this paper. Based on wet‐etching sputtered aluminum‐doped zinc oxide (ZnO:Al) substrates with optimized surface morphologies and photo‐electrical material properties, after adjusting individual single‐junction solar cells utilized in triple‐junction solar cells with various optimization techniques, we pay close attention to the optimization of tunnel recombination junctions (TRJs). By means of the optimization of individual a‐Si:H/a‐SiGe:H and a‐SiGe:H/µc‐Si:H double‐junction solar cells, we compensated for the open circuit voltage (V_oc) loss at the a‐Si:H/a‐SiGe:H TRJ by adopting a p‐type µc‐Si:H layer with a low activation energy. By combining the optimized single‐junction solar cells and top/middle, middle/bottom TRJs with little electrical losses, an initial efficiency of 15.06% was achieved for pin‐type a‐Si:H/a‐SiGe:H/µc‐Si:H triple‐junction solar cells. Copyright © 2014 John Wiley & Sons, Ltd.     

A three-dimensional architecture for a parallel processingphotosensing array [silicon retina application]

A three-dimensional architecture for a photosensing array has been developed. This silicon based architecture consists of a 10 x 10 array of photosensors with 80 microns diameter, through chip interconnects to the back side of a 500 microns thick silicon wafer. Each photosensor consists of a 300 x 300 microns pn-junction photodiode. The following processes were used to create this photosensing architecture: 1) thermomigration of aluminum pads through an n-type silicon wafer; 2) creation of pn-junction photosensors on one side of the wafer; and 3) creation of aluminum pad ohmic contacts to the thermomigrated, through chip interconnects and the substrate on the back side of the wafer. The electrical and optical characteristics of the three-dimensional architecture indicates that it should be well suited as a photosensing framework around which a "silicon retina" could be built.     

Interdigitated back‐contact heterojunction solar cell concept for liquid phase crystallized thin‐film silicon on glass

We present an interdigitated back‐contact silicon heterojunction system designed for liquid‐phase crystallized thin‐film (~10 µm) silicon on glass. The preparation of the interdigitated emitter (a‐Si:H(p)) and absorber (a‐Si:H(n)) contact layers relies on the etch selectivity of doped amorphous silicon layers in alkaline solutions. The etch rates of a‐Si:H(n) and a‐Si:H(p) in 0.6% NaOH were determined and interdigitated back‐contact silicon heterojunction solar cells with two different metallizations, namely Al and ITO/Ag electrodes, were evaluated regarding electrical and optical properties. An additional random pyramid texture on the back side provides short‐circuit current density (j_SC) of up to 30.3 mA/cm² using the ITO/Ag metallization. The maximum efficiency of 10.5% is mainly limited by a low of fill factor of 57%. However, the high j_SC, as well as V_OC values of 633 mV and pseudo‐fill factors of 77%, underline the high potential of this approach. Copyright © 2015 John Wiley & Sons, Ltd.     

Temperature influence on performance degradation of hydrogenated amorphous silicon solar cells irradiated with protons

This paper reports temperature influence on radiation degradation of hydrogenated amorphous silicon (a‐Si : H) solar cells. Degradation behaviors of a‐Si : H solar cells irradiated with protons at 331 K are compared with that at 298 K (room temperature). Variations with time in the post‐irradiation electrical properties are also investigated. It is found that the radiation degradation of the electrical properties at 331 K is significantly smaller than that at room temperature. Also, all the electrical properties (short‐circuit current, open‐circuit voltage, output maximum, and fill factor) recover with time after irradiation even at room temperature. The characteristic time of thermal annealing of short‐circuit current is larger as the temperature is higher. These results indicate that temperature during irradiation and elapsed time from irradiation to measurement is an important parameter for radiation degradation of a‐Si : H solar cells. Therefore, these parameters should be controlled in conducting the ground radiation tests. Copyright © 2012 John Wiley & Sons, Ltd.     

高掺杂氢化非晶硅薄膜

采用低浓度硅烷,低生长速率,在PECVD系统中制得高掺杂氢化非晶硅(N~+α-Si:H)薄膜,其电导率高达5～36Ω~(-1)cm~(-1)。应用该技术制成了新型二维电子气Si/N~+α-Si∶H异质结双极型晶体管,在硅微波功率异质结双极型晶体管研制上取得重大突破。     

Hybrid photovoltaic structures based on amorphous silicon and P3HT:PCBM/PEDOT:PSS polymer semiconductors

Hybrid thin film photovoltaic structures, based on hydrogenated silicon (Si:H), organic poly(3-hexythiophene):methano-fullerenephenyl-C61-butyric-acid-methyl-ester (P3HT:PCBM) and poly(3,4ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) films, have been fabricated. Organic semiconductor thin films were deposited by spin-coating technique and were exposed to radio frequency plasma enhanced chemical vapor deposition (RF PECVD) of Si:H films at deposition temperature T_d = 160 °C. Different types of structures have been investigated: H1) ITO/(p)SiC:H /P3HT:PCBM/(n) Si:H, H2) ITO/PEDOT:PSS/(i)Si:H/(n) Si:H and H3) ITO/PEDOT:PSS/P3HT:PCBM/(i)Si:H/(n)Si:H. Short circuit current density spectral response and current-voltage characteristics were measured for diagnostic of the photovoltaic performance. The current density spectral dependence of hybrid structures which contains organic layers showed improved response (50–80%) in high photon energy range (hν ≈ 3.1–3.5 eV) in comparison with Si:H reference structure. An adjustment in the absorbing layer thickness and in the contact material for ITO/PEDOT:PSS/(i)Si:H/(n)Si:H structure, resulted in a remarkably high short circuit current density (as large as 17.74 mA/cm²), an open circuit voltage of 640 mV and an efficiency of 3.75%.     

Hydrogen plasma passivation of bulk GaAs and Al0.3Ga0.7As/GaAs multiple-quantum-well structures on Si substrates

Hydrogen (H) plasma passivation effects on GaAs grown on Si substrates (GaAs on Si) are investigated in detail. H plasma exposure effectively passivates both the shallow and deep defects in GaAs on Si, which improves both the electrical and optical properties. It was found that the minority carrier lifetime is increased and the deep level concentration is decreased by the H plasma exposure. In addition, after H plasma exposure, room temperature photoluminescence (PL) for Al_0.3Ga_0.7As/GaAs multiple-quantum-well (MQW) on Si is enhanced with a decrease in the spectral width.     

Optimization and characterization of amorphous/crystalline silicon heterojunction solar cells

Amorphous hydrogenated silicon/crystalline silicon (a‐Si:H/c‐Si) heterojunction solar cells are investigated and optimized with regard to efficiency and simplicity of processing. Starting with a survey of a‐Si:H/c‐Si heterojunction solar cell results from the literature, we describe the fabrication steps of our a‐Si:H/c‐Si technology and analyze the electronic device properties by quantum efficiency, current–voltage, admittance, and capacitance–voltage measurements. The open‐circuit voltage and the fill factor of the a‐Si:H/c‐Si heterojunction solar cells under investigation are limited by recombination in the neutral zone of the crystalline Si absorber. Recombination at the a‐Si:H/c‐Si‐interface is subsidiary in respect of the limitation of the open‐circuit voltage. Our best n‐type a‐Si:H/p‐type c‐Si solar cell prepared without high‐efficiency features such as back‐surface field or surface texturing has an independently confirmed efficiency of 14.1% and an open‐circuit voltage of 655 mV. Copyright © 2001 John Wiley & Sons, Ltd.     

Current transport studies of amorphous n/p junctions and its application in a‐Si:H/HIT‐type tandem cells

This paper presents an understanding of the fundamental carrier transport mechanism in hydrogenated amorphous silicon (a‐Si:H)‐based n/p junctions. These n/p junctions are, then, used as tunneling and recombination junctions (TRJ) in tandem solar cells, which were constructed by stacking the a‐Si:H‐based solar cell on the heterojunction with intrinsic thin layer (HIT) cell. First, the effect of activation energy (E_a) and Urbach parameter (E_u) of n‐type hydrogenated amorphous silicon (a‐Si:H(n)) on current transport in an a‐Si:H‐based n/p TRJ has been investigated. The photoluminescence spectra and temperature‐dependent current–voltage characteristics in dark condition indicates that the tunneling is the dominant carrier transport mechanism in our a‐Si:H‐based n/p‐type TRJ. The fabrication of a tandem cell structure consists of an a‐Si:H‐based top cell and an HIT‐type bottom cell with the a‐Si:H‐based n/p junction developed as a TRJ in between. The development of a‐Si:H‐based n/p junction as a TRJ leads to an improved a‐Si:H/HIT‐type tandem cell with a better open circuit voltage (V_oc), fill factor (FF), and efficiency. The improvements in the cell performance was attributed to the wider band‐tail states in the a‐Si:H(n) layer that helps to an enhanced tunneling and recombination process in the TRJ. The best photovoltage parameters of the tandem cell were found to be V_oc = 1430 mV, short circuit current density = 10.51 mA/cm², FF = 0.65, and efficiency = 9.75%. Copyright © 2015 John Wiley & Sons, Ltd.     

Fabrication of Source/Drain Electrodes for a-Si:H Thin-Film Transistors Using a Single Cu Alloy Target

A Cu alloy/Cu alloy oxide bilayer structure was formed on an n ⁺-a-Si:H substrate using a single Cu alloy target. It was employed for the source/drain electrodes in the fabrication of a-Si:H thin-film transistors with good electrical performance, high thermal stability, and good adhesion. Transmission electron microscopy and electron energy-loss spectroscopy analyses revealed that the initial sputtering of the Cu alloy in O₂/Ar allowed for preferential oxidation of Si and the formation of a SiO _x /Cu-supersaturated a-Si:H bilayer at the copper oxide–a-Si:H interface. This bilayer turned into an SiO _x /Cu₃Si bilayer after annealing at 300°C. It provided a stable contact structure with low contact resistance.