EL2光淬灭过程中光电导增强现象原因新探  

New Explanation to EPC Phenomenon in EL2 Photoquenching

作　　者：徐波 王占国[1] 万寿科[1] 孙红[1] 张辉 杨锡权[1] 林兰英[1] 

机构地区：[1]中国科学院半导体研究所半导体材料科学开放实验室

出　　处：《Journal of Semiconductors》1994年第5期324-328,共5页半导体学报（英文版）

摘　　要：本文用光电导的实验方法对ＬＥＣＳＩ－ＧａＡｓ单晶中ＥＬ２能级的光淬灭过程进行了研究．通过对实验结果的分析，提出了一种解释ＥＬ２淬灭过程中ＥＰＣ现象起因的模型：光照前因补偿受主而已经电离的一部分ＥＬ２中心在近红外光照射下可通过从价带和其它深能级得到电子而被淬灭，使材料的费米能级下降，在价带中留下大量寿命很长的空穴，使光电导出现再上升．我们还发现ＥＰＣ的饱和值与材料的电子补偿度及热稳定性有一定的联系．Abstract We have studied the EL2 photoquenching process in undoped LEC SIGaAs by means of photoconductivity. Through the analysis of the experiment results, we put forward a new model which can explain the EPC phenomenon in the quenching: part of EL2 centres which have been ionized before illumination on account of compensation can be quenched under IR-illumination by getting electrons from valence band and other deep levels, lowering the dark Fermi level of the material,remaining in valence band a large amount of holes whose lifetime is quite long, and this results in the enhancement of photoconductivity. We have also found that the saturation value of EPC is somehow related to the electron compensation and thermal stability of the materials.

关 键 词：光电导增强 费米能级 砷化镓 单级 

分 类 号：TN304.23[电子电信—物理电子学]