The effect of solvent composition on stability and performance of CsPbIBr2
Summary: One-step spin coated CsPbIBr2 films, made with three different precursor solutions in order to investigate the effect of solvent composition on the processed film. Hypothesis: The best results will be obtained when the ratio of DMF to DMSO is equal to the ratio of iodine to bromine (1:2). Highlights: - Hypotheis supported, the film where the solvent mixture was made up of 67% DMSO and 33% DMF outperformed all other films when fresh. - The film where only DMSO was used showed higher stability when aged.
Steps to reproduce
0.5M solutions of CsPbIBr2 were prepared by dissolving equimolar ratios of CsI and PbBr2 in different mixtures of DMSO and DMF at 95°C for 90 minutes. Once a given solution was ready, 50µL of precursor solution was statically spin-coated onto the substrates at 4000RPM for 50 seconds. A two-step annealing procedure was employed where samples were held at 50°C and 250°C for 5 minutes respectively. To probe their stability, all the samples were stored in the laboratory, at 24°C and with a relative humidity of 50%, for 120 hours.