Nanomaterials @ Interfaces Research Group

We present an all solution, two-step method for the production of methylammonium lead iondide (MAPbI₃) perovskite thin films. Initially, PbS thin films were deposited on GaAs substrates. Subsequently, PbS films were transformed into PbI₂ following treatment with polyiodide solutions. In a second conversion step, MAPbI₃ films were obtained by reacting the films with methylammonium iodide solutions. The effect of the solvent on lead iodide morphology and consequently on MAPbI₃ morphology was demonstrated. Conversion rate was slower with increasing solvent polarity. Optimization of conversion parameters is crucial for reproducibly obtaining continuous and adhesive perovskite films. Photoluminescence measurements showed that chemical treatments can substantially enhance light emission from the films. This route for all-solution-processed perovskites enables control over film morphology while maintaining a simple and low-cost process.