Efficient CsPbBr₃ Quantum-Dot Light-Emitting Diodes Using Sputtered NiO Films as Hole Injection Layers

Perovskite quantum dots (QDs) have showed excellent optoelectronic properties to extend the application range of novel solid-state lighting, such as perovskite QD based LEDs (QD-LEDs). However, the traditional device structure of perovskite QD-LEDs employed PEDOT:PSS as a hole inject layer (HIL), which impairs stability due to acidic surface characteristics. This study proposes the sputtered NiO films as an HIL to replace acidic PEDOT:PSS. The NiO films with significantly different characteristics were prepared by controlling the sputtering parameters to investigate the devices' performance of NiO-based CsPbBr₃ QD-LEDs. The optimized device showed an excellent performance with maxima luminescence of 20,118 cd/m² and an external quantum efficiency (EQE) up to 3.63%.