Substrate-Dependent Photoconductivity Dynamics in a High-Efficiency Hybrid Perovskite Alloy
Substrate-Dependent Photoconductivity Dynamics in a High-Efficiency Hybrid Perovskite Alloy
复制标题
DOI：
10.1021/acs.jpcc.8b11783
复制
发表时间：
2018-12
期刊：
影响因子：
--
通讯作者：
Ali Moeed Tirmzi;Jeffrey A. Christians;Ryan P Dwyer;D. Moore;J. Marohn
中科院分区：
文献类型：
--
作者：
Ali Moeed Tirmzi;Jeffrey A. Christians;Ryan P Dwyer;D. Moore;J. Marohn
在TiO2、SnO2、ITO和NiO衬底上生长了(FA0.79MA0.16Cs0.05)0.97Pb0.84(0.16)2.97薄膜。通过测量薄膜和带电微悬臂梁之间的同相力和异相力来测试薄膜的导电性。我们跟踪了薄膜的电导率随时间、频率、光强度和温度(233-312K)的变化。与ITO和NiO相比，钙钛矿的导电率高，且与光无关。在二氧化钛和二氧化锡上，电导率在黑暗中很低，随着光照强度的增加而增加，并在去光后持续10‘S秒。当温度高于二氧化钛时，电导率在黑暗中的恢复速率与激活温度有关(Ea=0.58 eV)。令人惊讶的是，在低温下，二氧化钛和二氧化锡的光致导电性几乎是瞬间松弛的。我们使用离子-电子混合导体的传输线模型来说明所给出的测量结果对电子和离子电导的总和是敏感的。
Films of (FA0.79MA0.16Cs0.05)0.97Pb(I0.84Br0.16)2.97 were grown over TiO2, SnO2, indium tin oxide (ITO), and NiO. Film conductivity was interrogated by measuring the in-phase and out-of-phase forces acting between the film and a charged microcantilever. We followed the films’ conductivity versus time, frequency, light intensity, and temperature (233–312 K). Perovskite conductivity was high and light-independent over ITO and NiO. Over TiO2 and SnO2, the conductivity was low in the dark, increased with light intensity, and persisted for 10’s of seconds after the light was removed. At an elevated temperature over TiO2, the rate of conductivity recovery in the dark showed an activated temperature dependence (Ea = 0.58 eV). Surprisingly, the light-induced conductivity over TiO2 and SnO2 relaxed essentially instantaneously at a low temperature. We use a transmission-line model for mixed ionic–electronic conductors to show that the measurements presented are sensitive to the sum of electronic and ionic conductiv...