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

Abstract

AbstractPerovskite 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.