Improvement of Photoluminescence of Perovskite CH3NH3PbI3 by Adding Additional CH3NH3I during Grinding

Abstract
The organic-inorganic hybrid perovskite CH3NH3PbI3 has been a good candidate for many optoelectronic applications such as light-emitting diodes due to its unique properties. Optimizing the optical properties of the CH3NH3PbI3 material to improve the device performance is a hot topic. Herein, a new strategy is proposed to enhance the light emission of CH3NH3PbI3 phosphor effectively. By adding the reactant CH3NH3I powder in an appropriate proportion and simply grinding, the emission intensity of CH3NH3PbI3 is greatly improved. The advantages of the proposed method are swiftness, simplicity and reproducibility, and no requirement for a complex organic ligand. The mechanism of this phenomenon is revealed by x-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, photoluminescence, and temperature-dependent photoluminescence. This study offers a unique insight for optimizing the optical properties of halide perovskite materials.