Room temperature “one-pot” solution synthesis of nanoscale CsSnI3 orthorhombic perovskite thin films and particles

Abstract

The orthorhombic perovskite polymorph of cesium tin iodide (B-γ-CsSnI3) has been shown to possess an interesting combination of electrical and optical properties. Here we show that a simple “one-pot” method can be used for the solution synthesis and processing of nanoscale B-γ-CsSnI3 at room temperature. This method entails the dissolution of SnI2 and CsI powders in a specific combination of polar solvents, which results in a clear solution. Evaporation of the solvents results in the formation of B-γ-CsSnI3 on substrates, either in the form of nanocrystalline thin films or nanoparticles depending on the concentration of the solution. Thus, it is not necessary to synthesize B-γ-CsSnI3 phase a priori by vacuum melting or solid-state reaction methods before it can be solution processed, as has been implied in other studies. This has important implications for the solution synthesis and processing of nanoscale B-γ-CsSnI3 phase which may find potential new uses in solid-state dye-sensitized solar cells and optoelectronic devices of the future.