Double-stranded ligand modification of plasmonic nano-Au: CsPbBr3 perovskite nanocomposite for reinforced light-emitting performance

Perovskite quantum dots (PeQDs) have a wide range of potential applications in novel displays and solid-state lighting due to their excellent optoelectronic properties. However, insulating ligands around PeQDs can impair the performance of optoelectronic devices. This study proposes a surface ligand passivation of air-synthesized PeQDs modified by incorporation of didodecyl dimethyl ammonium bromide (DDAB), and addition of gold nanoparticles (AuNPs) to induce localized surface plasmon resonance (LSPR) to enhance the photonic characteristics and stability for plasmonic nano-Au:CsPbBr3 perovskite nanocomposite (PeNC), and successfully improved the light-emitting diodes (LEDs) characteristics. The photoluminescence intensity of the nano-Au:CsPbBr3 PeNC film was found to be 1.8-fold higher than that of the pure CsPbBr3 PeQDs film without DDAB. Compare with the pristine PeQD-LEDs without DDAB, the nano-Au:CsPbBr3 PeNC-LEDs thus fabricated exhibit a bright luminance of 6002 cd m−2, corresponding to a 5.4-fold improvement in external quantum efficiency (EQE), whose the device enhancement was attributed to the plasmonic effect of Au NPs.