微量硼掺杂非晶硅的瞬态光电导衰退及其光致变化  

Transient photoconductivity and its light-induced change of lightly boron-doped a-Si:H films

作　　者：张世斌[1] 孔光临[1] 徐艳月[1] 王永谦[1] 刁宏伟[1] 廖显伯[1] 

机构地区：[1]中国科学院半导体研究所凝聚态物理中心,表面物理国家实验室北京100083

出　　处：《物理学报》2002年第1期111-114,共4页Acta Physica Sinica

基　　金：国家重点基础研究发展规划项目 (批准号 :G2 0 0 0 0 2 82 0 1)资助的课题~~

摘　　要：利用EG&G的瞬态分析测试仪对微量硼掺杂的高氢稀释非晶硅薄膜的瞬态光电导作了测量 ,并研究了长时间曝光处理对瞬态光电导的影响 .发现薄膜的瞬态光电导衰退可以用双指数函数来拟合 ,说明在样品的光电导衰退过程中有两种陷阱在起作用 ,估算了陷阱能级的位置 .曝光处理后样品的光电导和暗电导不仅没有下降 ,而且还有所上升 ,薄膜的光敏性有所改善 .很可能曝光过程引起了硼受主的退激活 ,导致费米能级向导带边移动 ,使有效的复合中心减少 ,样品的光电导上升 .Transient photoconductivity and its light induced change were investigated by using a Model 4400 boxcar averager and signal processor for lightly boron\|doped a Si∶H films. The transient photoconductivities of the sample were measured at an annealed state and light\|soaked states. The transient decay process of the photoconductivity can be fitted fairly well by a second\|order exponential decay function, which indicates that the decay process is related with two different traps. It is noteworthy that the photoconductivity of the film increases after light soaking. This may be due to the deactivity of the boron acceptor B - 4, and thus some of the boron atoms can no longer act as acceptors and drives E F to shifts upward. Consequently, the number of effective recombination centers may be reduced and so the photoconductivity increases.

关 键 词：非晶硅薄膜 光致变化 硼掺杂 光电导衰退 瞬态响应 

分 类 号：O472.3[理学—半导体物理]