포지티브 에이징 및 후처리 기술을 통한 InP기반 양자점 발광 다이오드의 성능 및 안정성 향상

Abstract

In this study, we uncover remarkable aging behavior in InP-based quantum-dot-based light-emitting diodes (QD-LEDs) encapsulated with epoxy, where the current efficiency increases over time. Our investigation reveals that positive aging is driven by the diffusion of thiol molecules among the components of the epoxy resin. As the aging process progresses, the epoxy components not only mitigate the photoluminescence (PL) loss in the QDs caused by the presence of ZnMgO nanoparticles (NPs) and the Al electrode on top of the QD layer but also reduce the electron injection into the QD layer, leading to improved efficiency. Moreover, we find that the post-annealing treatment has a significant impact on the performance of the device. By carefully modulating the diffusive behavior, the optimal aging process results in a significant enhancement in the overall performance of the green InP-based QD-LED. With a maximum luminance of 15,340 cd/m2 and a maximum external quantum efficiency (EQE) of 5.13%, the improvement is approximately 30-fold. This study sheds light on the intricate interplay between the aging process, thiol molecules, and post-annealing treatment in QD-LEDs and opens avenues for further optimization and improvement.