Efficient halide perovskite light-emitting diodes with emissive layer consisted of multilayer coatings

Abstract

Perovskite light-emitting diodes (PeLEDs) with multilayer coatings consisted of CsPbBr3 and 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene as the emissive layer are demonstrated. The effects of the multilayer coatings upon both the electroluminescent performance and the device stability are investigated. The PeLEDs with a coating pair number of 4 (four-pair PeLEDs) obtain a maximum current efficiency of 9.16 cd/A and a maximum external quantum efficiency of 2.37%, corresponding to more than 4-fold enhancement to those of the control PeLEDs. Furthermore, the half-lifetime of the four-pair PeLEDs is about 50 times longer than that of the control PeLEDs. Such enhancements are attributed to the improved film morphology, enhanced electron injection and transport capability, widened exciton formation zone, and better exciton confinement.