Ultrafast Rejuvenation of Aged CsPbI₃ Quantum Dots and Efficiency Improvement by Sequential 1-Dodecanethiol Post-Treatment Strategy

Metal halide perovskite CsPbI₃ quantum dots (QDs) have sparked widespread research due to their intriguing optoelectronic. However, the CsPbI₃ QDs undergo inevitable aging and luminescence quenching caused by the weak binding ability of oleate (OA^-)/oleylammonium (OAm⁺), hindering further practical application. Herein, we have realized ultrafast rejuvenation of the aged CsPbI₃ QDs that have lost their photoluminescence performance based on a 1-dodecanethiol (DDT) surface ligand to restore the outstanding red light emission with a high photoluminescence quantum yield (PLQY) from 25 to 90%. Furthermore, CsPbI₃ QDs with DDT surface treatment maintain a cubic phase and high PLQY value even after 35 days. The DDT ligands can form a strong bond with Pb²⁺ and passivate I^- ion vacancies, enhancing radiative recombination efficiency and thereby improving the PLQY of the QDs. The stable yet easily accessible surface of the DDT-capped CsPbI₃ QDs was successfully employed as white LEDs and exhibited considerable enhanced luminous performance, suggesting promising application in solid-state lighting fields.