非线性伏安特性实验数据处理的研究

用FD-UI-A非线性元件伏安特性实验仪测量了普通二极管和稳压二极管伏安特性,研究了用软件处理非线性数据的过程.研究结果表明,普通二极管和稳压二极管的伏安特性呈现出非线性,但其-呈良好的线性关系,其斜率反映了二极管材料的导电特性.     

稳压管伏安特性测量中电表的正确接法

研究电流表接法对稳压二极管伏安特性测量结果的影响。理论分析和实验研究表明,测量稳压二极管的伏安特性时,在稳压管的正向死区和反向截止区电流表应该内接,在其正向导通区和反向击穿区电流表应该外接。这样,只要电流表内阻足够小且电压表内阻足够大,测量系统误差就远小于1%。     

某些锗隧道二极管的老化现象

对n区掺砷、p区为铟加百分之一镓、快速合金而成的锗隧道二极管做老化实验,发现某些二极管当加正向偏压时,过剩电流增加。这类二极管典型的伏安特性,如图1所示。由图可知,77°K时,峯值出现在234mV处,比我们实验用的一般锗隧道二极管的峯值电压大。在正向电压80mV处出现拐点d~2I/dV~2=0。反向隧道电流小。室温下,加正向电流50mA,老化结果,伏安特性曲线不变。高温下,正向老化结果,过剩电流单调增加。图2表示正向伏安特性的变化。曲线1,2,3和 4分别表示高温(95℃)正向5O     

利用霍尔电流传感器对“示波法显示稳压二极管伏安特性曲线”实验的改进

针对"示波法显示稳压二极管的伏安特性曲线"存在的问题,提出了改进方法。利用霍尔电流传感器解决原有电路在原理上的缺陷。模拟仿真和实验结果均显示,改进后的检测电路具有更好的示波显示效果和易调节性,可以更加准确的显示稳压二极管的伏安特性曲线。     

浅谈伏安法测二极管的特性

高等学校试用的《普通物理实验》一书中,关于伏安法测二极管的特性实验(以下简称伏安特性实验),是通过测出二极管反向饱和电流I_e、正向各种偏压U_D及其对应的电流I_D,算出二极管温度等效电压的倒数(q/kT),再与室温时的理论值比较,让学生了解二极管的正向伏安特性。该实验和一些较能精确测定半导体PN结电流-电压关系的方法相比,不仅具有方法简单,直观性强,数据易处理等优点,而且使学生能够运用普物实验手段,认识半导体二极管这一重要特性,它是大学低年级可以开设的基础实验之一,但是如按课本上的要求测量,误差很大(只有理论值的一半左右),达不到比较满意的效果,本文通过分析误差产生的主要根源,谈谈原实验方案的弊端及改进意见。     

非线性光子晶体的单向透射性

利用非线性时域有限差分方法(FDTD)对光从某些一维缺陷层掺杂克尔非线性介质的四分之一波长光子晶体的正反两个不同方向入射时对应的一般透射特性进行了数值分析.计算表明：一定频率范围及一定光强范围的光从非线性光子晶体的正向入射时,透射率是其从非线性光子晶体相反方向入射时的数倍,具有单向透射性,表现为全光二极管的行为.进一步对交替介质层由空气和金红石(TiO2)组成而非线性缺陷层由聚合物(polydiacetykene 9-BCMU)组成的光子晶体模型的透射特性进行了数值分析.在某一频率和强度附近,该模型的正向透射率是反向的6倍左右,表明其可作为一种全光二极管使用.     

小型超导电源系统退磁保护回路建模与仿真

计算了采用二极管等效电压源模型和等效电阻模型的退磁回路电流响应和二极管功耗,分析了两个模型的特点和差异,在此基础上,为了进一步提高精度,充分考虑了二极管的非线性特性,以实际二极管伏安特性进行曲线拟合建立函数关系式得到二极管非线性模型,代入回路方程并求解。综合对比各模型的仿真结果后,得出采用二极管非线性模型和等效电压源模型能更好地模拟退磁保护响应。     

对二极管特性曲线的再认识

通过对二极管实测正向特性曲线分段进行一元线性回归处理，证明了二极管伏安特性的数学表示公式，只适用于特性曲线的指数弯曲阶段，并不适用于整条曲线。     

PN结正向伏安特性曲线随温度的变化

介绍了在不同温度下，PN结正向伏安特性曲线的自动测量方法。讨论了PN结伏安特性与温度的关系．由于正向结电压小于内建电势差，温度升高或正向结电压增加，正向结电流将增大，温度升高反向结电流也相应增加．当温度趋向OK时。正向结电压趋向内建电势差。     

利用二极管正向伏安特性的测量训练学生对系统误差的修正

在用安培表外接法进行二极管正向伏安特性曲线的测量中,加入系统误差修正,强化学生对系统误差分析与修正的训练。     

Effect of the image forces on the volt-ampere characteristics of a metal-α-Si contact

In the paper an analytic calculation is carried out of the volt-ampere characteristics of a Schottky barrier diode on amorphous silicon for an exponential distribution of the density of localized states in the mobility gap of -Si. Explicit expressions are written for the volt-ampere characteristics with and without the inclusion of the image forces. It is shown that taking into account the image forces in the case of an intimate contact can lead to a substantial increase in the reverse currents through the diode, at the same time changing slightly the slope of both the forward and reverse branches of the volt-ampere characteristics plotted on a semilogarithmic scale.Translated from Izvestiya Vysshikh Uehebnykh Zavedenii, Fizika, No. 2, pp. 88–92, February, 1985.     

示波器在教学实践中的演示应用

总结并推出应用示波器进行教学演示、实验测量中的几个特殊测量方法.如电容的充放电波形、RLC串联电路的阶跃响应、RC串并联网络的选频特性、二极管的伏安特性曲线、三极管的输出特性曲线等的演示及测量方法.     

Research on reverse recovery characteristics of SiGeC p-i-n diodes

This paper analyses the reverse recovery characteristics and mechanism of SiGeC p-i-n diodes. Based on the integrated systems engineering (ISE) data, the critical physical models of SiGeC diodes are proposed. Based on heterojunction band gap engineering, the softness factor increases over six times, reverse recovery time is over 30% short and there is a 20% decrease in peak reverse recovery current for SiGeC diodes with 20% of germanium and 0.5% of carbon, compared to Si diodes. Those advantages of SiGeC p-i-n diodes are more obvious at high temperature. Compared to lifetime control, SiGeC technique is more suitable for improving diode properties and the tradeoff between reverse recovery time and forward voltage drop can be easily achieved in SiGeC diodes. Furthermore, the high thermal-stability of SiGeC diodes reduces the costs of further process steps and offers more freedoms to device design.     

Mechanism of Charge Transfer in Gallium Arsenide Light-Emitting Structures

The results of experimental investigations into the volt-ampere characteristics (VACs) of gallium arsenide light-emitting diode structures are presented. It is established that VACs of single- and multimesa structures are similar. It is demonstrated that the dependence of the current density on the voltage for the examined structures is well described in the context of the VAC theory of pin diodes.     

Fabrication and characteristics of lateral Ti/4H-SiC Schottky barrier diodes

This paper describes the fabrication and characteristics of the lateral Ti/4H-SiC Schottky barrier diodes (SBDs). SBDs are fabricated by nitrogen ion implantation into p-type 4H-SiC epitaxial layer. The implant depth profile is simulated using the Monte Carlo simulator TRIM. Measurements of the reverse I－V characteristics demonstrate a low reverse current, that is good enough for many SiC-based devices such as SiC metal-semiconductor field-effect transistors, and SiC static induction transistors. The parameters of the diodes are extracted from the forward I－V characteristics. The barrier height φ_b of Ti/4H-SiC is 0.95 eV.     

GaAs PIN二极管电热特性

通过T-CAD软件建立了PIN二极管的电学模型和热学模型,模拟了PIN二极管的稳态与瞬态特性。研究了PIN二极管器件在正反偏压和脉冲电压下的电学特性及热学特性,讨论了PIN二极管的I层厚度与温度的关系,模拟得到了不同I层厚度的稳态与瞬态响应曲线、得到了与器件内部温度的关系。模拟结果表明:随着I层厚度的增加,器件内部最高温度增长减慢,器件内部最高温度区由结区位置向器件的中间位置移动。     

Phase interaction in GaAs contacts with group I metals and its relationship to the degradation of structures with a Schottky barrier

The methods of Rutherford back scattering of helium ions and x-ray diffraction and electron microscope analysis are used to study phase interaction in GaAs contacts with layers of group I metals (Cu, Ag, Au) with annealings in a hydrogen atmosphere. The nature of the interaction and the mechanisms of degradation of the volt-ampere characteristics of Schottky barrier diodes are discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 16–22, September, 1985.