Hutter Eline M, Savenije Tom J
Department of Chemical Engineering, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands.
ACS Energy Lett. 2018 Sep 14;3(9):2068-2069. doi: 10.1021/acsenergylett.8b01106. Epub 2018 Jul 18.
The relationship between the dipole moment of the methylammonium cation and the optoelectronic properties of lead halide perovskites remains under debate. We show that both the temperature-dependent charge carrier mobility and recombination kinetics are identical for methylammonium and cesium lead iodide, indicating that the role of the monovalent cation is subordinate to the lead iodide framework. From the observation that for both perovskites the electron-hole recombination is thermally activated, we speculate that the bandgap is slightly indirect.
甲基铵阳离子的偶极矩与卤化铅钙钛矿的光电特性之间的关系仍存在争议。我们表明，甲基铵和碘化铯铅的温度依赖性电荷载流子迁移率和复合动力学是相同的，这表明单价阳离子的作用从属于碘化铅框架。基于两种钙钛矿的电子-空穴复合均受热激活这一观察结果，我们推测其带隙略呈间接带隙。
