Highly bright perovskite light-emitting diodes based on quasi-2D perovskite film through synergetic solvent engineering.

Recently, quasi-two dimensional (2D) perovskites have attracted great interest as they can be facilely fabricated and yield high photoluminescence quantum yield. However, the luminance and the efficiency of perovskite light-emitting diodes (PeLEDs) based on quasi-2D perovskites are limited by the carrier transport and the crystallization properties of the quasi-2D perovskite films. Herein, a synergetic solvent engineering approach is proposed to improve the crystallinity and the carrier transport by optimizing the film morphology of the quasi-2D perovskite films. Consequently, the maximum luminance of green PeLEDs based on quasi-2D PEA 2 (MAPbBr 3 ) 2 PbBr 4 perovskite is dramatically enhanced from 4000 cd m -2 to 18 000 cd m -2 and the current efficiency increases from 3.40 cd A -1 to 8.74 cd A -1 . This work provides a promising way to control the morphology and the crystallinity properties of quasi-2D perovskite films for high-performance optoelectronic devices.