High Radiance of Perovskite Light-Emitting Diodes Enabled by Perovskite Heterojunctions

Metal-halide perovskites (MHPs) have made incredible achievements in the past few years, especially in the area of perovskite light-emitting diodes (PeLEDs). Nevertheless, hole transport layers (HTLs) used in most highly efficient PeLEDs usually have low hole mobilities in the range of 10(-4)-10(-6) cm(2 )V(-1) s(-1), much lower than that of MHPs, resulting in severe roll-off and low radiance of the devices. Here, methylammonium lead iodide (MAPbI(3)) is successfully deposited on top of methylammonium lead chloride (MAPbCl(3)) using orthogonal solvent to form heterojunction PeLEDs (HJ-PeLEDs). Due to the high hole mobility of MAPbCl(3) approximate to 42 cm(2 )V(-1) s(-1), the HJ-PeLEDs exhibit a peak external quantum efficiency of 10.7% and a high radiance of 157 W sr(-1) m(-2) at a low applied voltage of 3.9 V. Furthermore, the large-area (28 cm(2)) HJ-PeLEDs made by blade coating shows a uniform and high radiance of approximate to 180 W sr(-1) m(-2). This work provides a novel strategy to fabricate bright and large-area PeLEDs to meet the requirements of commercial applications.

Automated summary

This study demonstrates a novel strategy to fabricate bright and large-area PeLEDs by depositing MAPbI(3) on top of MAPbCl(3) using orthogonal solvents, resulting in high external quantum efficiency and radiance, meeting the requirements of commercial applications.