Organic Tetrabutylammonium Cation Intercalation to Heal Inorganic CsPbI_3 Perovskite
【摘要】：The in-situ formation of reduced dimensional perovskite layer via post-synthesis ion exchange has been an effective way of passivating organic-inorganic hybrid perovskites. In contrast, cesium ions in Cs-based inorganic perovskite with strong ionic binding energy cannot exchange with those well-known organic cations to form reduced dimensional perovskite. Herein, we demonstrate that tetrabutylammonium(TBA+) cation can intercalate into Cs PbI3 to effectively substitute the Cs cation and to form one-dimensional(1 D) TBAPbI3 layer in the post-synthesis TBAI treatment. Such TBA cation intercalation leads to in-situ formation of TBAPbI3 protective layer to heal defects at the surface of inorganic Cs PbI3 perovskite. The TBAPbI3-CsPbI3 perovskite exhibited enhanced stability and lower defect density, and the corresponding perovskite solar cell devices achieved an improved efficiency up to 18.32% compared to 15.85% of the control one. Our findings would inspire further investigation and development of reduced dimensional perovskite protection strategy for inorganic perovskites.