Solvent‐Free Mechanochemical Synthesis of a Systematic Series of Pure‐Phase Mixed‐Halide Perovskites MAPb(I<sub><i>x</i></sub>Br<sub>1−<i>x</i></sub>)<sub>3</sub> and MAPb(Br<sub><i>x</i></sub>Cl<sub>1−<i>x</i></sub>)<sub>3</sub> for Continuous Composition and Band‐Gap Tuning
Sheng Tang, Xinyu Xiao, Jing Hu, Bo Gao, Hunglin Chen, Zongyang Peng, Jianchun Wen, Masanao Era, Dechun Zou
Abstract
Abstract Hybrid perovskites have recently received much attention in optoelectronic applications. However, hybrid perovskites are unstable in a humid environment. Mixed halide perovskites (MHPs) show enhanced stability and band‐gap tunability upon engineering of their halide composition. Here, MHPs are prepared through a solvent‐free mechanochemical synthesis (MCS) route that allows superior control over halide compositions than the solvent synthesis routes (SS). The MCS route eliminates the problem in the preparation of MAPb(I x Br 1− x ) 3 with continuously varying x , while maintaining the material properties and suppressing phase segregation present in SS routes. UV‐vis absorption and X‐ray diffraction patterns confirm the production of the desired pure‐phase MHPs. For MAPb(I x Br 1− x ) 3 (0≤ x ≤1), with increased ratio of halide ( x ), the cubic phase gradually transforms into the tetragonal phase and band‐gap tunability is accomplished. The MCS route for the preparation of MHPs is a very promising and efficient technique for superior control in optoelectronic properties, leading to improved control in fabrication approaches.