A donor–acceptor ligand boosting the performance of FA0.8Cs0.2PbBr3 nanocrystal light-emitting diodes

Abstract

A donor–acceptor ligand, 3-amino-2-bromo-6-methoxypyridine (ABMeoPy), was introduced to passivate FA_0.8Cs_0.2PbBr₃ nanocrystals (NCs) by a post-processing method. The donor–acceptor interaction can greatly enhance the coordination bond of pyridine-Pb²⁺, and improve FA_0.8Cs_0.2PbBr₃ NC performance with 95.99% photoluminescence quantum yield (PLQY), 6-month stability in solution, and 26% trap density decrease. In the light of ABMeoPy passivation of FA_0.8Cs_0.2PbBr₃ NCs, the maximum luminance, the maximum current efficiency, and EQE of light-emitting diodes (LEDs) increased 69%, 110%, and 111%, respectively. The strategy of using D–A molecules to passivate perovskite NCs is quite simple and effective, which can be widely promoted in perovskite-based LEDs or solar cells.