CAJ | 학술논문

研究了非晶硅薄膜的瞬态光电导的光致变化情况.用通常的非晶态半导体的瞬态光电流的乘方规律和稳态光电导的扩展指数规律都不能对试验数据进行很好的拟合,而采用两个指数函数相加的形式可以对实验数据进行很好的拟合.这表明非晶硅薄膜长时间的衰退不是由带尾态决定,而是由深的陷阱决定的.两个指数函数的衰退分别对应于距导带0.52eV和0.59eV的两个陷阱,这两个陷阱可以被指认为带隙中的荷负电中心.光照后,带隙中的复合中心增加,导致电子寿命的减少,从而引起光电导的衰退.
연구료비정규박막적순태광전도적광치변화정황.용통상적비정태반도체적순태광전류적승방규률화은태광전도적확전지수규률도불능대시험수거진행흔호적의합,이채용량개지수함수상가적형식가이대실험수거진행흔호적의합.저표명비정규박막장시간적쇠퇴불시유대미태결정,이시유심적함정결정적.량개지수함수적쇠퇴분별대응우거도대0.52eV화0.59eV적량개함정,저량개함정가이피지인위대극중적하부전중심.광조후,대극중적복합중심증가,도치전자수명적감소,종이인기광전도적쇠퇴.
Light induced changes in a-Si∶H films are investigated by transient photoconductivity.The transient photoconductivity decay data can neither be fit well by common power-law for transient photocurrent in amorphous semiconductors,nor by stretched exponential rule for transient decay from the steady state in photoconductivity.Instead,the data are fit fairly well with a sum of two exponential functions.The results show that the long time decay is governed by deep traps rather than band tail states,and two different traps locating separately at 0.52 and 0.59eV below Ec are responsible for the two exponential functions.They are designated as negatively charged dangling bond D- centers.The light-induced changes in photoconductivity are attributed mainly to the decrease in electron lifetime caused by the increase of recombination centers after light soaking.