Controlling Orientation Diversity of Mixed Ion Perovskites: Reduced Crystal Microstrain and Improved Structural Stability

Shasha Zhang; Shaohang Wu; Rui Chen; Weitao Chen; Yuqian Huang; Hongmei Zhu; Zhichun Yang; Wei Chen

doi:10.1021/acs.jpclett.9b01180

Controlling Orientation Diversity of Mixed Ion Perovskites: Reduced Crystal Microstrain and Improved Structural Stability

J Phys Chem Lett. 2019 Jun 6;10(11):2898-2903. doi: 10.1021/acs.jpclett.9b01180. Epub 2019 May 17.

Authors

Shasha Zhang¹, Shaohang Wu¹, Rui Chen¹, Weitao Chen¹, Yuqian Huang¹, Hongmei Zhu¹, Zhichun Yang¹, Wei Chen^{1

2}

Affiliations

¹ Wuhan National Laboratory for Optoelectronics , Huazhong University of Science and Technology , Luoyu Road 1037 , Wuhan 430074 , China.
² Shenzhen Key Laboratory of Nanobiomechanics , Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055 , Guangdong , China.

PMID: 31091877
DOI: 10.1021/acs.jpclett.9b01180

Abstract

Formamidinium lead iodide (FAPbI₃)-based perovskite has attracted increasing attention of researchers due to its lower band gap and improved thermal stability. However, it is structurally unstable and easy to phase-transfer at room temperature. Here, we improve the structural stability of perovskite by controlling its orientation diversity. XRD results show that incorporating CsBr into FAPbI₃ is effective to adjust the crystal plane stacking. For the first time, an orientation diversity factor (ODF) is identified, and it is found that an increased ODF is propitious to decrease the lattice distortion and relax the microstrain in the crystal, boosting the efficiency and stability of the perovskite solar cells (PSCs). The optimized inverted PSC based on FA_0.85Cs_0.15PbI_2.85Br_0.15 achieves efficiency of 17.59% and presents ignored performance decline under continuous light-soaking for 500 h.