Interfacial diffused reaction at two-phase solution induced crystallization for high-quality perovskite single crystals

Abstract

Realizing high quality organic–inorganic hybrid perovskite semiconductors with low trap states and reduced toxic-lead (Pb) usage is crucial for the development of sustainable clean photovoltaics. Here, two-phase technology with the advantages of rapid reaction, a simple operation process, low cost, and low-toxicity compared to the traditional method has been developed for the first time for the synthesis of Pb-free MASnI₃ single crystals with good crystallinity and stability. The study demonstrates that the reactant concentration, reaction time and temperature are key factors affecting the quality of the MASnI₃ single-crystal. The fabricated MASnI₃ single-crystal has an absorption onset of 1043 nm and exhibits a narrow bandgap of 1.19 eV. Photodetectors based on the MASnI₃ single crystal exhibit good repeatability. The growth mechanism is also proposed in this article, and MA₃Bi₂I₉ and MAPbI₃ single crystals were also successfully synthesized based on this technology. Therefore, this two-phase approach offers a novel and effective strategy for growing high-quality single crystals.