Enhanced Performance of Pure-red Perovskite Light-emitting Diodes by Surface Modification with Guanidine Acetate
Metal-halide perovskite materials have attracted much attention in recent years due to their excellent op-toelectronic properties,which can be used to fabricate light-emitting layers of light-emitting diodes.However,there are a large number of defects on the surface of perovskite and at the interface between the perovskite layer and the transport layer,which seriously affects the performance and stability of the device,and the surface/interface treat-ment has been proven to be an effective way to reduce the interface defects and improve the performance of the de-vice.Therefore,a surface treatment strategy of adding guanidine acetate to the extractant was reported,which could effectively reduce the surface defects and improve the morphology of the perovskite film,thereby increasing the pho-toluminescence quantum yields of perovskite film from 64%to 79%.The maximum efficiency of the devices prepared based on the surface treatment of perovskite films can reach 11.66%and the maximum brightness exceeds 1 285 cd·m-2,which is significantly better than that of the control devices(6.69%,689 cd·m-2),and also shows better stabili-ty.This study provides an effective perovskite surface treatment strategy to improve the performance and stability of perovskite light-emitting diodes.