Growing MASnI3 perovskite single-crystal films by inverse temperature crystallization

Perovskite single-crystal films are promising candidates for high-performance perovskite optoelectronic devices due to their optoelectrical properties. However, there are few reports of single-crystal films of tin based perovskites. Here, for the first time, we realize the controllable growth and preparation of lead-free tin perovskite MASnI(3) single crystals via inverse temperature crystallization (ITC) strategy with gamma-butyrolactone (GBL) as solvent. The solubility characteristics of MASnI(3) in GBL are clarified by quantitative analytical method. Highly repeatability experiments are further demonstrated using this unique solubility and ITC properties. Sequentially, using space limiting method, tin perovskite MASnI(3) single-crystal thin films are fabricated with micron-scale thickness, which is highly desired for efficient tin perovskite solar cells. Our MASnI(3) single-crystal thin films show typical single-crystalline features including strongly optical absorbance with sharp absorption edges, pure-phase x-ray diffraction patterns, and absence of Sn(IV) x-ray photoelectron spectroscopy. We believe that our findings will further broaden the application prospects of tin perovskite MASnI(3) single crystals and cause a new upsurge in exploring the field of lead-free perovskite single-crystal growth.

Automated summary

This study demonstrates the controllable growth and preparation of lead-free tin perovskite MASnI(3) single crystals using the inverse temperature crystallization strategy with gamma-butyrolactone as solvent. The solubility characteristics of MASnI(3) in GBL are clarified, and highly repeatable experiments are demonstrated. Single-crystal thin films of MASnI(3) with micron-scale thickness are fabricated using the space limiting method, showing typical single-crystalline features.