Ultrathin nano-layered boron nitride stabilizing perovskite quantum dot-based light-emitting diodes

Perovskite quantum dot-based light-emitting diodes (QLEDs) have been regarded as promising emitters for lighting and displays. However, the operational stability still greatly hinders their practical applications. Here, we introduce ultrathin nano-layered boron nitride (BN) as buried interfacial layer to enhance device stability. As an effective blocking layer, BN not only interacts with perovskite to passivate interface defects and eliminate ion migration channel, but also directly suppresses ion migration. Meanwhile, BN makes exciton recombination behavior and electrical transport properties of perovskite QDs less sensitive to the heat. Resultantly, BN-optimized QLEDs achieved an average EQE of 30.05% and extrapolated operational lifetime T₅₀ of 25,263 h at an initial luminance (L₀) of 100 cd m^-2, which is 1.7-fold and about 100-fold improvement compared to control devices, respectively. In this work, integrating 2D materials into perovskites through interface engineering provides a pragmatic tactic to enhance the performance of halide perovskite-based LEDs.