Enhancing the Phase Stability of Inorganic α-CsPbI3 by the Bication-Conjugated Organic Molecule for Efficient Perovskite Solar Cells

• DOI: 10.1021/acsami.9b12579
• Publication Date: 2019-10-07T11:25:35Z
• Authors: Xihong Ding; Molang Cai; Xiaoyan Liu; Yong Ding; Xuepeng Liu; Yahan Wu; Tasawar Hayat; Ahmed Alsaedi; Songyuan Dai
• Keywords: Organic molecules

Inorganic CsPbI3 perovskite has demonstrated promising potentials for photovoltaic applications, whereas the black polymorph (α phase) of was easily prone to converting into yellow phase (δ under ambient moist environment, which restrained its practical application and further studies severely. In this study, p-phenylenediammonium iodide (PPDI) employed posttreat films controlling conversion, strengthening moisture resistance, improving device performance. The multiple roles PPDI were as follows: (1) avoiding spontaneous octahedral tilting by ionic bonds between NH3+ PPD2+ I– [PbI6]4–; (2) enhancing hydrophobicity induced exactly exposed oil-wet (hydrophobic) benzene rings; (3) passivating surface defects filling I vacancies. As a result, after treatment, mutable a-CsPbI3 could maintain α at least 30 d in dry air (<20% RH). solar cells with treatment exhibited reproductive performance champion power conversion efficiency (PCE) 10.4, 91% initial PCE retained storage 504 h dark box without any encapsulation.