High-Performance Blue Quasi-2D Perovskite Light-Emitting Diodes via Balanced Carrier Confinement and Transfer

Highlights A new concept to optimize the passivating agents for the balance of the carrier confinement and transfer in blue quasi-2D perovskites. The moderate tributylphosphine oxide is introduced into the quasi-2D perovskites to simultaneously strengthen the carrier confinement for massive radiative recombination as well as promote efficient carrier transfer in the quasi-2D perovskites. High-efficient and stable blue PeLEDs are achieved with an external quantum efficiency of 11.5% and a very long operational stability of 41.1 min without any shift of the electroluminescence spectra.