Abstract
Extensive investigation of the passivating agents has been performed to suppress the perovskite defects. However, very few attentions have been paid to rationally design the passivating agents for the balance of the carrier confinement and transfer in quasi-2D perovskites, which is essential to achieve high-performance perovskite LEDs (PeLEDs). In this work, tributylphosphine oxide (TBPO) with moderate carbon chain length is demonstrated as a decent passivator for the quasi-2D perovskites by strengthening the carrier confinement for massive radiative recombination within the perovskites, and more importantly providing efficient carrier transfer in the quasi-2D perovskites. Benefiting from these interesting optoelectronic properties of TBPO-incorporated perovskites, we achieve high-efficient blue PeLEDs with an external quantum efficiency up to 11.5% and operational stability as long as 41.1 min without any shift of the electroluminescence spectra. Consequently, this work contributes an effective approach to promote the carrier confinement and transfer for high-performance and stable blue PeLEDs.