Synergistic effect of indium doping and chlorine surface passivation on CsPbI₃ perovskite quantum dots for deep-red...

Deep-red CsPbI₃ perovskite quantum dots (PeQDs) are essential for high-efficiency perovskite light-emitting diodes (PeLEDs) because of their high color purity and high photoluminescence quantum yield (PLQY). The synergetic strategy of indium (In) doping and chlorine (Cl) surface passivation not only partially replaced Pb²⁺ ions with the smaller ionic In³⁺ but also filled I^- vacancies by Cl^- on the surface, maintaining the humidity stability for more than 24 days and yielding excellent PLQY. Benefiting from this synergetic strategy, deep-red (approximately at 683 nm) CsPbI₃ PeLEDs showed a maximum luminance and external quantum efficiency (EQE) of 311 cd m^-2 and 8.32%, respectively.