高效蓝光钙钛矿发光二极管的埋底界面修饰和光耦合策略

Buried interface modification and light outcoupling strategy for efficient blue perovskite light-emitting diodes

Perovskite light-emitting diodes(PeLEDs)exhibit remarkable potential in the field of displays and solidstate lighting.However,blue PeLEDs,a key element for practical applications,still lag behind their green and red counterparts,due to a combination of strong nonradiative recombination losses and unoptimized device structures.In this report,we propose a buried interface modification strategy to address these challenges by focusing on the bottom-hole transport layer(HTL)of the PeLEDs.On the one hand,a multifunctional molecule,aminoacetic acid hydrochloride(AACl),is introduced to modify the HTL/perovskite interface to regulate the perovskite crystallization.Experimental investigations and theoretical calculations demonstrate that AACl can effectively reduce the nonradiative recombination losses in bulk perovskites by suppressing the growth of low-n perovskite phases and also the losses at the bottom interface by passivating interfacial defects.On the other hand,a self-assembly nanomesh structure is ingeniously developed within the HTLs.This nanomesh structure is meticulously crafted through the blending of poly-(9,9-dioctyl-fluorene-co-N-(4-butyl phenyl)diphenylamine)and poly(n-vinyl carbazole),significantly enhancing the light outcoupling efficiency in PeLEDs.As a result,our blue PeLEDs achieve remarkable external quantum efficiencies,20.4%at 487 nm and 12.5%at 470 nm,which are among the highest reported values.Our results offer valuable insights and effective methods for achieving high-performance blue PeLEDs.