Effect of A-site cations on MAPbBr₃ perovskite light-emitting diodes

Abstract Perovskite light-emitting diodes (PeLEDs) have gained widespread acceptance in the field of optoelectronics due to their exceptional performance. In this paper, CsBr was added to MAPbBr 3 emissive layer in order to reduce the non-radiative recombination defects of perovskite films. The maximum luminance of the optimized device is 4248 cd m −2 , and the maximum external quantum efficiency is 0.44%, which is 162% and 69% higher than that of the undoped device, respectively. This is primarily attributable to the fact that the incorporation of CsBr into the MAPbBr 3 perovskite results in a reduction in the surface roughness of the perovskite film. Meanwhile, CsBr can passivate the internal defects of perovskites and inhibit the defect-assisted non-radiative recombination, thus improving the radiative recombination efficiency and leading to the enhancement of the device’s optoelectronic performance. These results have a positive effect on the further in-depth study of the performance and preparation process of PeLEDs.