Li Zhenzhen, Xu Jia, Zhou Shijie, Zhang Bing, Liu Xiaolong, Dai Songyuan, Yao Jianxi
ACS Appl Mater Interfaces. 2018 Nov 7;10(44):38183-38192. doi: 10.1021/acsami.8b11474. Epub 2018 Oct 26.
All-inorganic cesium lead perovskites have emerged as alternative absorbing layers in solar cells owing to their superb thermal stability compared with the organic-inorganic hybrid perovskites. However, the desired cubic CsPbI phase forms at a high temperature and suffers from a phase transition to the orthorhombic yellow phase at room temperature. A developed nonstoichiometric method is applied to fabricate CsPbIBr ( x < 1) films by adding excess CsBr into the precursor solution. The excess CsBr in the precursor solution helps to produce a microstrain in the lattice to stabilize the cubic CsPbI phase at low temperature and incorporate a small part of Br into the CsPbI lattice. At the optimal CsBr concentration (0.5 M), the corresponding solar cell achieves a power conversion efficiency of 10.92%. This work provides an effective way to stabilize the cubic CsPbIBr ( x < 1) phase at low temperature to further improve the performance of all-inorganic perovskite solar cells.
与有机-无机杂化钙钛矿相比，全无机铯铅钙钛矿因其出色的热稳定性而成为太阳能电池中替代吸收层。然而，理想的立方相CsPbI在高温下形成，且在室温下会发生向正交黄相的相变。一种改进的非化学计量方法被用于通过向前驱体溶液中添加过量的CsBr来制备CsPbIBr（x < 1）薄膜。前驱体溶液中过量的CsBr有助于在晶格中产生微应变，从而在低温下稳定立方相CsPbI，并使一小部分Br掺入CsPbI晶格中。在最佳CsBr浓度（0.5 M）下，相应的太阳能电池实现了10.92%的功率转换效率。这项工作提供了一种在低温下稳定立方相CsPbIBr（x < 1）的有效方法，以进一步提高全无机钙钛矿太阳能电池的性能。
