Optimized Design Calculation of Temperature Sensitive Diode

对温度敏感元件提出一种优化设计计算方法，建立了硅温敏二级管的数学模型．在此基础上，用复合形法对硅温敏二级管的结构参数和材料参数进行优化设计计算；用最小二乘法计算了结构参数、材料参数的变化对其主要电学性能参数的影响；并对计算结果进行了分析、讨论．A method of optimized design calculation applied to the near linearity sensor is proposed. The mathematical model of the temperature sensitive diode is founded. The optimized constructive parameter and material parameter of the silicon temperature sensitive diode are calculated by the complex method. The effect of the variation of constructive parameter and material parameter on the electrical parameter are calculated by the least square fit method, and the results are analyzed.福建省自然科学基金!（F5005

Ambipolar Diffusion Length in Semi insulating GaAs

分析了半绝缘（ S I） gA AS 表面光伏的特点和公式.用表面光伏方法测量了不同砷压热处理 S I gA AS 单晶的双极扩散长度，用 1.1 μM 红外吸收法测量 E l2 浓度，并对测量结果作了分析和讨论.指出双极扩散长度 lA 是反映 S I gA AS 质量的一个重要电学参数.The features and the formulae of the surface photovoltage of semi insulating GaAs are analysed.The ambipolar diffusion length in undoped SI GaAs crystal by the thermal treatment in the different ambient of As atmosphere is measured by using the surface photovoltage method, and the EL2 concentration is measured by the 1.1 μm infrared absorption method,and the measured results are discussed.It is pointed out that the ambipolar diffusion length, L a is an important electrical parameter characterizing the quality of SI GaAs

The Influence Upon SI GaAs's Character by Different Arsenic Pressure in the Process of Heat Treatment

采用 5种经不同砷压但相同生长温度 ( 1 0 0 0℃ )和时间 ( 5 h)处理的半绝缘 ( SI) Ga As样品 ,利用表面光伏 ( SPV)方法 ,测量和计算了 SI-Ga As在室温 ( 30 0 K)下的主要施主浓度 EL2 、禁带宽度 EgΓ和双极扩散长度 La,并从理论上给出了相应的解释 .On the basis of the comparison on five kinds of SI GaAs sa mple through different arsenic pressure but same growth temperature(1000℃) and time(5 h) in the process of heat treatment,some important characteristic parameters for S I GaAs in 300 K have been measured and computed by the steady-state surface ph otovoltage method, the EL 2 concentr ation, the energy gap E gΓ and the ambipolar diffusion length L a . Furthermore, the experimented results are analyzed theoretically.福建省教育厅基金资助项目 ( JB0 10 16

The energy gap E_gΓ of semi-insulating Ga As studied by the SPV method

根据所建立的半绝缘 (SI)GaAs的禁带宽度EgΓ 公式 ,利用表面光伏 (SPV)方法的测量结果 ,计算了室温下 5种样品的EgΓ 值 ,并对其中之一进行了 2 1- 30 0K温度范围的EgΓ 计算 ,确认了SPV方法对研究SI -GaAs禁带宽度的可行性 .According to the gotten formula of the energy gaps(E gΓ ) of the semi-insulating(SI) GaAs, and using the measured result by the surface photovoltage method, the energy gaps of five kinds of sample in 300?K are computed. In addition, the E gΓ of one of the samples from 21 to 300?K are computed, it is pointed out that the SPV method is a effective one for studying the energy gap of SI-GaAs.福建省教育厅科研资助项目 (JB0 10 16

Study on Optimization of Electrical Properties of Temperature Sensitive Diode

从优化设计的需要出发，推导了温敏二极管灵敏度、线性度和串联电阻等电参数的理论公式.采用优化分析法，讨论了影响温敏二极管性能诸多因素的矛盾关系，提出温敏二极管的设计原则及解决相关矛盾的方法.理论分析得到实验结果的有力支持.The theory formulate of the sensitivity, the linearity and the series resistor of the temperature Sensitive diode are derived for the needs of the optimized design.The contradictory relations of the factors which decide the electrical properties of the temperature sensitive diode are discussed.The methods to resolve the above contradictory relations and the principle of the optimized disign of the temperature sensitive diode are proposed.The theoretical analyses are in agreement with the experimental results.福建省自然科学基

古田山10种主要森林群落类型的α和β多样性格局及影响因素

古田山国家级自然保护区地处中亚热带,地形复杂,森林群落类型丰富。我们在保护区内10种主要森林群落类型中网格化布置并调查了79个20 m×20 m样地,分析了不同群落类型内及相互间的α(Shannon-Wiener指数)、β(Horn-Morisita相异性指数)多样性分布格局及其影响因素。结果表明:(1)α多样性主要受到群落类型、海拔和坡向的影响。α多样性在不同群落类型间差异显著,并且随海拔升高、坡向从南到北,α多样性增大。(2)β多样性主要受到群落类型和海拔的影响,受空间距离的影响不显著。不同群落类型间的β多样性显著大于同一群落类型内部,并且随海拔升高β多样性增大。总体而言,群落类型和海拔是古田山森林群落α和β多样性的主要影响因子,表明生境过滤等机制对该区域的森林物种多样性格局起着主要作用

Study of the Characteristic and Parameters of Semiconductor Material

提出超晶格 (Al As/ Ga As)和应变超晶格 (Gex Si1-x/ Si,Inx Ga1-x As/ Ga As)光伏效应的机理 ,测量了不同温度下的光伏谱 ,光伏曲线反映了台阶二维状态密度分布并观察到跃迁峰 .计算了导带和价带子带的位置和带宽 ,根据宇称守恒确定光跃迁选择定则 ,对跃迁峰进行指认 .研究了光伏随温度变化、激子谱峰半高宽随温度和阱宽的变化 ,讨论谱峰展宽机制中的声子关联 ,混晶组分起伏及界面不平整对线宽的影响 .测量了元素和化合物半导体单晶材料的室温、低温下的表面光电压谱 ,推导了有关计算公式 ,计算得出电学参数 (L、n0 、μ、S、W)、深能级和表面能级位置、带隙和化合物组分 ;分析了电学参数的温度关系 ;由双能级复合理论 ,研究了少子扩散长度与深能级关系 ,计算了深能级浓度和参数 .在不同条件下研制了二氧化锡 /多孔硅 /硅 (Sn O2 / PS/ Si)和二氧化锡 /硅 (Sn O2 / Si) ,测量了它们的光伏谱 ,分析表明它们存在着异质结 .当样品吸附还原性气体 (H2 、CO、液化石油气 )时 ,光电压有明显变化 ,因此可做为一种新的敏感元件 .分析了它们的吸附机理 ,计算了有关参数The mechanism of the photovoltaic effect for superlattices(AlAs/GaAs) and strained superlattices(Ge xSi 1-x /Si,In xGa 1-x As/GaAs)are discussed. The photovoltage spectra at different temperatures have been measured. The curves of SPV reflect the step like distribution of two dimensional state density, and transition peaks have been observed. The levels and bandwidths of the subbands have been calculated. The transition speaks are assingned according to the selection rule for optical transition based on the conservation law of parit. The changed in photovoltage with temperature, the full width of half maxium of the transition peaks as a function of temperature and well width for different samples are investigated. The influences of exciton phonon coupling, alloy disorder and interface roughness on the broading mechanism of the transition peaks are discussed. The surface photovoltage of element and compounds single crystal semiconductors are measured at room and low temperatures. Some calculation formules are derived. The electrical parameters (L,n 0,μ,S,W),deep levels and surface level, energy gap and composition of the compounds are determined. The temperature dependence of the electrical parameters are analyzed. The dependence of minority carrier diffusion length on deep level are studied by double level recombination theory. The concentration and parameters of deep levels are calculated. Tin Oxide/Porous Silicon/Silicon(SnO 2/PS/Si)and Tin Oxide/Silicon are fabricated at different conditions. The photovoltage spectra of SnO 2/PS/Si and SnO 2/Si have been studied. It is shown that there exist heterojunctions in SnO 2/PS/Si and SnO 2/Si. The photovoltage changes evidently when the sample absorbes reducing gas (H 2,CO,liguified petroleum). The experimental results indicate that SnO 2/PS/Si or SnO 2/Si is a good material for gas sensor. The mechamism for the gas absorption of SnO 2/PS/Si and SnO 2/Si are discussed. The parameters are calculated.国家自然科学基金资助项目!(技准 36 1号 ;6 86 6 0 52 ;;59172 10 1) ;; 教育部科研资助项目 ;; 福建省自然科学基金资助项目!(F950