PbI_2掺杂对CH_3NH_3PbI_3光电性能的影响

Effect of PbI_2 Doping on Photoelectrical Properties of CH_3NH_3PbI_3

采用溶液生成法制备了有机铅卤化钙钛矿(CH_3NH_3PbI_3)晶体粉末,并以过量的PbI_2对其进行掺杂,采用X射线衍射谱(XRD)技术研究了掺杂前后样品的晶体结构变化。表面光电压谱(SPS)和相位谱(PS)显示掺杂前后的CH_3NH_3PbI_3均为p型半导体,但后者有更强的光伏响应。场诱导表面光电压谱(FISPS)表明:当加正电场时,掺杂前后的CH_3NH_3PbI_3均表现为p型半导体的载流子特性,当加负偏压时掺杂后的CH_3NH_3PbI_3易形成反型层,出现光伏反转,且外加负偏压越大,光伏反转区域越大,表现出双极导电特性。

Organolead halide perovskite（CH3NH3PbI3）crystal powder was prepared by means of solution,and some with excess of PbI2 doping.The crystal structure changes of obtained powers were characterized by X-ray diffraction spectrum（XRD）technology.According to the results of surface photovoltage spectroscopy（SPS）and phase spectrum（PS）,the CH3NH3PbI3 before and after doping were both p-type semiconductor,but the surface photovoltage response intensity of the latter CH3NH3PbI3 after doping was more stronger.Field induced surface photovoltage spectroscopy（FISPS）shows that appling positive electric bias does not change the p-type features of the both CH3NH3PbI3.However,applying negative electric bias can be expected to result in the formation of an inversion layer in the CH3NH3PbI3 after doping which leads to surface photovoltage inversion.With the greater of negative bias,the inversion area is larger,making it show a bipolar conductive properties.