Tetraoctylammonium bromide-passivated CsPbI3-xBrx perovskite nanoparticles with improved stability for efficient red light-emitting diodes

In this study, we demonstrate a ligand-exchange reaction using tetraoctylammonium bromide (TOAB) salts for the as-synthesized CsPbI3 perovskite nanoparticles (NPs) to ensure NPs with stable and improved device performance. TOAB passivation provides a negatively polarized halide-rich surface, higher steric hindrance, and a small amount of Br- anions in the NP lattice to significantly improve the NP stability. The red NP-based light-emitting diodes (NpLEDs) based on TOAB-passivated NPs also exhibited excellent performance because of shorter ligands and stable NPs, with a maximum luminescence of 1345 cd/m(2) and a maximum external quantum efficiency of 11.7%. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study demonstrates the use of TOAB salts for ligand-exchange reactions to improve the stability and device performance of CsPbI3 perovskite nanoparticles. TOAB passivation provides a negatively polarized surface, higher steric hindrance, and a small amount of Br- anions in the NP lattice, significantly enhancing NP stability. The red NP-based light-emitting diodes (NpLEDs) based on TOAB-passivated NPs exhibit excellent performance with a maximum luminescence of 1345 cd/m(2) and a maximum external quantum efficiency of 11.7%.