Enhanced Performance and Stability of Pure Red Perovskite Light-Emitting Diodes Through Controlled Passivation of Perovskite Emitter Films

Abstract

Efforts have been devoted to optimizing the optoelectronic properties of perovskite emitters with the aim of achieving high-performance full-color display technology using perovskite light-emitting diodes (PeLEDs). In this study, we propose a method for producing high-quality perovskite emitting by incorporating octylammonium iodide (OAI), which has been specifically designed for pure red PeLEDs. The strategic inclusion of OAI enhances the quality of perovskite films by suppressing severe grain boundaries and reducing defect densities within the films. Through systematic characterizations involving surface morphology, photoluminescence properties, and electrical characteristics, we elucidate how the incorporation of OAI leads to the formation of high-quality emitting layers in red PeLEDs. This results in bright, pure red electroluminescence (EL) and improved stability. The optimized passivation using OAI demonstrates several notable improvements compared to pristine devices, demonstrating a maximum EL (ELMax) of 1274.9 cd m–2, a maximum external quantum efficiency (EQEMax) of 16.47%, and a low turn-on voltage of 1.59 V, whereas the pristine device achieves an ELMax of 409.6 cd m–2 and an EQEMax of 3.26%. Remarkably, the operational, spectral, and storage stabilities exhibited by OAI-passivated devices are exceptional, a half-lifetime exceeding 9 hours. This represents a significant advancement in high-performance pure red PeLED technologies.

Keywords: Perovskite light-emitting diodies (PeLEDs), Electroluminescence, Pure-blue, Operative stability, External quantum efficiency