Ligand-engineered CsPbBr3 perovskite quantum dots for self-healing and stable performance

This paper presents a method for enhancing the environmental stability of all-inorganic perovskite quantum dots (CsPbBr₃) through ligand engineering. To address the challenge of insufficient stability when directly exposed to the natural environment, the study employed trioctylphosphine, lead stearate, and chlorobenzene as solvents. The results indicate that the modified quantum dots exhibited self-healing behavior after 30 days of exposure to corrosive solutions used in LED fabrication processes, with a significant recovery in photoluminescence intensity. Compared to CsPbBr₃, the intensity increased by 29-fold, 104-fold, 250-fold, and 65-fold after exposure to water, ZnO, TiO₂, and Poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) solutions, respectively. Additionally, their luminescence intensity at 100 °C increased by 116%. Stability tests under various natural atmospheric conditions confirmed that the time to complete failure reached 1900 h, 5950 h, approximately 3 years, and approximately 24.5 years in humid-hot, forest, laboratory, and low-temperature environments, respectively. These self-healing quantum dots provide valuable insights for quantum dot stability research and the outdoor application of devices. Perovskite quantum dots offer easy synthesis and high performance but suffer from poor heat and moisture stability due to organic components. Here, the authors demonstrate a ligand-engineering strategy to improve the environmental stability of all-inorganic CsPbBr₃ perovskite quantum dots using trioctylphosphine, lead stearate, and chlorobenzene.