Preparation and luminescence study of green lighting MAPbBr₃ perovskite thin films in air environment

In recent years, organic-inorganic hybrid metal halide perovskites have attracted widespread attention in the field of optoelectronics due to their advantages such as high color purity, solution processability, and adjustable band gap. Perovskites, as the light-emitting functional layer material of light-emitting devices, are very sensitive to water and oxygen in the air. Usually, the preparation of such perovskite films needs to be carried out in a glove box filled with inert gas, which makes it difficult to achieve industrial mass production. This study attempts to prepare perovskite luminescent films in an air environment. In the preparation of perovskite precursor solution, three preparation methods, pure MAPbBr₃, MAPbBr₃ + GBA, and MAPbBr₃ + GBA + PEO, were used, respectively. The luminescence properties and film quality of the formed films were compared. The main conclusions could be drawn as follows: 1) The addition of GBA and PEO improves the photoluminescence properties of the film, among which the MAPbBr₃ + GBA + PEO film has the best luminescence performance. 2) SEM morphology observations show that pores in the MAPbBr₃ + GBA + PEO film are smaller, the grains are more tightly bonded, and XRD analysis shows that its crystallization quality is better, proving that the addition of GBA and PEO is beneficial to passivating the defects of the perovskite film. 3) The prepared MAPbBr₃ + GBA + PEO film was placed in air for a week, and the PL intensity remained at 95.5% of the initial value, indicating that it has good stability in the air environment, and the film was also used to make a perovskite light-emitting diode that can emit green light, further confirming the feasibility of synthesizing perovskite light-emitting films in air. This study has a certain role in promoting the synthesis of perovskite light-emitting films in air and large-scale industrial production.