Influence of fumed silica and PMMA on optical properties of blue-emitting CH₃NH₃PbBr₃ perovskite nanocrystals

Abstract

Fabricating highly efficient and great optical properties of blue organic-inorganic halide perovskite (OIHP) has proven difficult and continues to be a source of significant interest. Herein, we successfully synthesized blue-emitting CH3NH3PbBr3 perovskite using a ligand assisted reprecipitation process, followed by embedding in fumed silica and poly-methylmethacrylate (PMMA) matrix. By adding fumed silica, the photoluminescence (PL) peak spectrum of CH3NH3PbBr3 was blue-shifted from 481 to 477 nm. Furthermore, OIHP also exhibited a blue shift from 477 nm to 471 nm after being embedded in the PMMA matrix. On the other hand, the OIHP absorbance spectrum shifted from 451 nm to 426 nm, which correlates to the blueshift in the PL peak spectrum. The emergence of two peaks in the absorbance spectrum indicates that nanoparticles with small size distribution have grown on the OIHP. This phenomenon demonstrates that the OIHP has a strong quantum confinement effect. Therefore, the results demonstrated that CH3NH3PbBr3/SiO2/PMMA composite films have great optical properties, which is promising for their uses in potential optoelectronic applications.