Formation of Distributed Local Heterojunction to Enhance NIR Emission Due to the Effective Carrier Transfer

Abstract Perovskite light‐emitting devices (PeLEDs) have emerged as a highly promising contender for the next generation of lighting and display technologies. During the nucleation and crystallization process, numerous defects are commonly formed on the surface and grain boundaries as a result of the ionic characteristics of perovskite, especially in an air environment. These defects ultimately contribute to the deterioration of the photoelectron properties. In this study, CsPbI₃ nanocrystals (NCs) solution is introduced into ethyl acetate antisolvent as an additive, resulting in the high‐quality perovskite films under ambient conditions. The introduction of CsPbI₃ NCs has been found to increase the grain size and improve the uniformity of perovskite films while also effectively passivating defects. More significantly, the utilization of CsPbI₃ NCs leads to the formation of a 0D/3D local heterojunction that is distributed throughout the MAPbI₃ film. These distributed heterojunctions significantly increase both the carrier concentration and the photoluminescence performance. With the incorporation of doped perovskite films, Silicon (Si) ‐based PeLEDs demonstrate enhanced efficiency, achieving a maximum external quantum efficiency of 12.6% in ambient conditions. Additionally, these devices exhibit a prolonged operational half‐life of 80 minutes. This study presents a novel methodology for fabricating high‐efficiency Si‐based PeLEDs that exhibit exceptional electroluminescence characteristics.