Study On Dual Passivation Of Defect For High-efficient Perovskite Light-emitting Diodes

As advanced optoelectronic semiconductor materials,metal halide perovskites have attracted the attention of researchers in photovoltaic field due to their continuously adjustable bandgap,high defect tolerance,and low manufacturing cost.In addition,perovskite LEDs,as promising devices for next-generation display revolution,exhibit high brightness,high color-purity and wide color gamut.During the operation of the LED,charge carriers are consumed through the process of non-radiative recombination,radiative recombination and Auger recombination,but only through radiative recombination can photons be effectively generated.Therefore,in order to obtain high efficient perovskite LEDs,it is essential to suppress the trap-induced non-radiative recombination.This article will compare the effects of those carrier recombination process.From the viewpoint of trap-induced non-radiative recombination,we summarize the existing methods which can efficiently suppress the formation of defects or passivate defects in perovskite LEDs.In the main part of the article,we propose a dual passivation strategy of defect,and conduct an in-depth study on this strategy.1.Dual passivation of defects for high-efficient perovskite LEDFrom the perspective of theoretical calculation and experimental characterization,it can be proved that the dual passivation additive can effectively bond with the perovskite and passivate defects in the perovskite simultaneously.Compared with the control films,the perovskite films with dual passivation additive exhibit better photoelectric properties.In addition,perovskite LED with an EQE of 20.9%has been achieved,which is the record efficiency for deep red perovskite LEDs.2.The effect of dual passivation strategy on other properties of perovskite LEDThrough transient pulsed electroluminescence measurements,we conduct deep study on carrier property in our perovskite LEDs,and proved its potential for the application of electrically pumped lasers.In addition,this strategy can effectively suppress the ions migration in perovskite,thereby hysteresis effect and the phase segregation in the mixed halide perovskite are alleviated.Finally,the operational stability and shelf stability of the devices are also greatly improved.