Effect of Dispersion Solutions on Optical Properties and Stability of CsPbBr3 Perovskite Nanocrystals

Abstract Long-term storage stability of cesium lead based perovskite nanocrystals especially at ambiant conditions is a vital challenge which deters their advancement in photovoltaic applications. Here, CsPbBr3 perovskite nanocrystals is synthesized by hot injection method, and the stability of CsPbBr3 nanocrystals is investigated when dispersed in individual solvents such as Toluene, Acetone, and Ethanol as well as the combination of solvents. The synergistic effect of toluene-non-polar molecule and acetone-a polar molecule was studied and their effect on the stability of CsPbBr3 in terms of retention of optical absorption and emission is investigated. A combination of toluene and acetone as solvents is found to be best medium for dispersion of CsPbBr3 perovskite nanocrystals which remains stable for around two weeks with 63%, 60% retention of luminescence and absorbance. Further, by addition of PVP polymer (0.05 wt.%) in dispersion solution, the luminescence and absorbance are retained up to ~70% and ~78% for more than two months storage time. The storage stability of combination of mix solvents is important for the applications in which stable dispersion of perovskite materials ought to prepare in polar or non-polar solvents.