Suppressing Interfacial Nonradiative Recombination with Acetate Interlayer for High-Performance Pure Blue Perovskite LEDs

Abstract

Rapid crystallization kinetics of quasi-2D blue perovskite precursors during spin-coating leads to uneven grain growth, porous film morphology, and increased interfacial defects, which exacerbates nonradiative recombination at the bottom of the perovskite film. Interface engineering is recognized as one of the most effective strategies to suppress such interfacial nonradiative recombination. Thus, CH3COOLi is intercalated between PEDOT:PSS and the perovskite. Benefiting from CH3COOLi’s dual effects of retarding the crystallization rate and reducing the formation of n=1 phase at the bottom of the perovskite film, quasi-2D blue PeLED achieves a peak external quantum efficiency of 9.9% (under 3.35 mA cm-1) at 474 nm.