The photoluminescence quantum yield (PLQY) and charge carrier mobility of organic-inorganic perovskite quantum dots (QDs) have been significantly enhanced through the optimization of crystallinity, surface passivation, and solid-state ligand exchange.

Crystallinity was optimized by selecting solvents with appropriate Effective solvent fields (Esol). Post-ligand adding (PLAP) and post-ligand exchange processes (PLEP) further increased PLQY by reducing non-radiative recombination and surface defect states.

Specifically, solid-state PLEP improved charge carrier mobility by using short alkyl chain ligands, which increased packing density in films. This process resulted in a maximum hole mobility of 6.2 × 10−3 cm² V⁻¹ s⁻¹ with hexyl ligands, significantly higher than pristine QDs. Additionally, PLEP treatment led to a 2.5 times higher current efficiency in perovskite QD-LEDs compared to pristine devices, due to enhanced charge carrier mobility and PLQY. – Journal cover design by scapiens

https://pubs.rsc.org/en/content/articlelanding/2018/nr/c8nr00806j#!divAbstract