n型LEC-GaAs中E_5能级的研究

Study on the E_5 Energy Level in N-type LEC-GaAs

本文采用DLTS及光电容技术对n型未掺LEC-GaAs材料中的深中心进行了研究.通过对E_5能级阈值附近光电离截面谱的温度效应的分析,提出了此能级向导带的电子发射存在两步光热激发过程的模型,算出激发态位于导带下23meV处.用多声子过程解释了E,能级光阈值能小于热激活能的现象.

Using DLTS and photo-capacitance methods, deep energy level in undoped n-type LEC-GaAs material have been studied.On the basis of the temperature effect of the photoionizationcross section spectrum close to the threshold energy for E_5,the model that the two-step photo-thermal excitation behaviour exists in the excitation procers for electrons from E_3 to the con-duction band is suggested.The excited-state position has been determined to be 23 mev belowthe conduction band.