Efficient Perovskite-Based Near-Infrared Micro Light-Emitting Diode and Size-Effect Analysis

The state-of-the-art micro-LEDs based on group III-V chips face the challenges in size-effect and mass transfer. Recently, perovskite LEDs have rapidly developed, and their solution processability may show great advance in the miniaturization and integration with driving circuit. However, the majority of research on perovskite micro-LEDs (micro-PeLEDs) have been focused on visible light, leaving the study of near-infrared micro-PeLEDs in its infancy. Herein, we report a photolithography-compatible method for the first demonstration of near-infrared micro-PeLEDs. A peak external quantum efficiency of 5.9% is achieved with 50~\mu m pixel size and the size-effect of micro-PeLEDs is further discussed. The hyperspectral PL imaging shows the photoluminescence (PL) properties of the pixelized perovskite are not greatly affected by pixel size, and the electroluminescence (EL) analysis reveals that the size-related EL reduction is mainly caused by the inefficient current injection, which is easily to be optimized. Therefore, our work reveals that the perovskite with dispersed grains have an outstanding potential in the field of miniaturization.