不同湿度环境下CH3NH3PbI3薄膜的退化过程

实验分析了在15%、50%和90%RH湿度条件下CH₃NH₃PbI₃薄膜退化过程.通过XRD测量发现不同湿度环境中CH₃NH₃PbI₃薄膜的退化产物为PbI₂,且在90%相对湿度(RH)环境下还观测到了退化中间产物水合物(CH₃NH₃)₄PbI₆·2H₂O.不同湿度环境中CH₃NH₃PbI₃薄膜退化速度不同,湿度越大,退化速度越快.通过载流子动力学的测量发现随着退化时间增长,CH₃NH₃PbI₃薄膜光生载流子数量不断减小.低湿度环境下CH₃NH₃PbI₃薄膜在退化过程中表现出缺陷钝化现象,载流子复合寿命随退化时间呈先上升后下降趋势.而在高湿度条件下,CH₃NH₃PbI₃薄膜出现缺陷增加现象,载流子复合寿命随退化时间呈下降趋势.

On degradation process of CH3NH3PbI3 film in different humidity conditions

The degradation process of CH₃NH₃PbI₃ films under 15%, 50% and 90% relative humidity(RH)was analyzed.The degradation product of CH₃NH₃PbI₃film in different humidity environments was found to be PbI₂ according to XRD measurement.The intermediate product was also observed in the 90% RH environment, which is similar like(CH₃NH₃)₄PbI₆·2H₂O.CH₃NH₃PbI₃ film exhibits a faster degradation rates in high RH environment.During CH₃NH₃PbI₃ film degradation process its photo induced carriers quantity also decreases with aging time.In high RH environment carriers lifetime of CH₃NH₃PbI₃ film reduces monotonously with aging time.While in low RH environment carrier lifetime increases at first stage of degradation process, which means that low RH atmosphere can passivate defects in CH₃NH₃PbI₃ thin film.