5-Ammonium Valeric Acid Iodide to Stabilize MAPbI3 via a Mixed-Cation Perovskite with Reduced Dimension

• DOI: 10.1021/acs.jpclett.0c02528
• Publication Date: 2020-09-15T19:11:27Z
• Authors: Ning Wei; Yuetian Chen; Yanfeng Miao; Taiyang Zhang; Xingtao Wang; Hao Wei; Yixin Zhao
• Keywords: Valeric acid; Ammonium iodide; Thermal Stability

5-Ammonium valeric acid iodide (AVAI) has been widely known as a stabilizer to enhance the stability of MAPbI3 perovskite, but its role and function is still under exploration. The typical 2D perovskites AVA2PbI4 have proposed capping layer for stabilization. Here, novel AVA-MA mixed-cation perovskite AVAMAPbI4 found show more even compact coverage than AVA2PbI4. A simple post-treatment on films by using AVAI isopropanol solution can fabricate such sample. This effectively passivates surface defects reduces charge-carrier recombination, enabling AVAI-MAPbI3 exhibit improved against thermal moisture stress. Finally, AVAI-MAPbI3-based solar cells also an enhanced photovoltaic performance with champion PCE up 20.05% stability.