Efficient and Bright All-Vacuum-Deposited Perovskite Light Emitting Diode via Guanidinium Doping and an Ultrathin Lithium Bromide Interfacial Layer

Abstract

Perovskite light emitting diodes (PeLEDs) are highly promising for next-generation displays owing to their exceptional emissive properties. However, their complex fabrication, often relying on interleaved solution processing and vacuum deposition, hinders scalable mass production. Here, we present a strategy for high-performance, all-vacuum-deposited PeLEDs. By incorporating vacuum-sublimed nitrogen-containing additives, guanidinium bromide, we effectively suppress intrinsic bulk defects in perovskite films and mitigate nonradiative recombination. Furthermore, an ultrathin, vacuum-deposited alkali metal halide top layer is introduced to heal the defective interface by compensating for the loss of bromide during thermal evaporation and improving crystallinity. Integrating these advanced perovskite films with vacuum-sublimed organic transporting layers resulted in PeLEDs demonstrating a maximum luminance exceeding 164,000 cd/m2 and external quantum efficiencies (EQEs) of 14.83%. Our EQE approaches the current vacuum-device record, while the luminance represents a more than 5-fold improvement over most of the previously reported all-vacuum-deposited devices, highlighting a significant leap toward industrially viable PeLED displays.