掺GeZnSe的稳恒光电导及其局域性效应

在一定的温度以下 ,某些半导体材料的光电导效应在激发光源撤去以后会持久地保持下去 ,当温度升高超过这个温度 (称为淬变温度 )以后 ,这种持续的光电导现象会消除 ,称为稳恒光电导现象 .而且这种光电导效应具有很强的局域性 .采用电学测量方法 ,通过测量激光照射前后电导率随温度的变化研究了掺 Ge的 Zn Se的稳恒光电导效应 ,结果发现淬变温度高达 2 1 0 K的稳恒光电导效应 .并通过研究光电阻随光照位置变化的趋势研究了这种光电导的局域性特性 ,结果发现在淬变温度以上局域性随稳恒光电导消失而消失

PPC Effect and Localization in Ge-doped ZnSe Epilayer

Some semiconductor materials exhibit a persistent photoconductivity, which is strongly localized in the region which is pre\|exposed to the light below a certain temperature.When the temperature exceed this temperature (called quench temperature),the persistent photoconductivity and the localization will disappear.The persistent photoconductivity with its localization effect of the Ge\|doped ZnSe semiconductor is studied by measuring its conductivityies before and after laser illumination.The results show that the quench temperature of PPC is about 210K.The localization is also studied by the electrically measuring method.The variation of the resistivity with the position of laser beam scanning the sample below the quench temperature is not observed when the temperature is higher than the quench temperature.The localized PPC effect is mainly attributed to the Coulomb interaction theoretically.