Highly Luminescent and Stable CsPbI₃ Perovskite Nanocrystals with Sodium Dodecyl Sulfate Ligand Passivation for Red-Light-Emitting Diodes

CsPbI3 perovskite nanocrystals (NCs) have recently emerged as promising materials for optoelectronic devices because of their superior properties. However, the poor stability NCs induced by easy ligand desorption represents a key issue limiting practical applications. Herein, we report stable and highly luminescent black-phase passivated novel ligands sodium dodecyl sulfate (SDS). Theoretical calculation results reveal stronger adsorption energy SDS molecules at surface than that commonly used oleic acid. As result, defect formation caused loss during purification process is greatly suppressed. The optimized SDS-CsPbI3 exhibit significantly reduced defects, much enhanced stability, photoluminescence efficiency. red light-emitting diodes based on demonstrate an external quantum efficiency 8.4%, which shows 4-fold improvement compared to acid-modified NCs.