P‐9.3: High‐Performance Red Perovskite QLEDs Based on Low‐Toxicity Zn‐Pb Alloy Perovskite QDs Passivated by Inorganic Ligands

Abstract

The development of low-cost, solution-processable, low-toxicity and air-stable perovskite quantum dots (PeQDs) light-emitting diodes (QLEDs) holds promise for next-generation display technologies. However, especially air-stable α-CsPbI3 PeQDs and corresponding light-emitting devices still face great challenges due to their inherent ionic structural properties and phase instability. Here, a dual strategy based on Zn 2+ doping and inorganic ligand SCN-surface passivation was developed to obtain improved, stable and near-100% photoluminescence quantum yields (PL QYs) of α-CsPbI3 QDs. High-efficiency red perovskite QLEDs are also fabricated, and the best device has a maximum brightness of 4800 cd/m 2 and an external quantum efficiency (EQE) of 5.98%. More importantly, compared with pure CsPbI3QLEDs, the operating stability of perovskite QLEDs based on Zn 2+ doping and SCN-surface passivation is greatly improved in air environment, and their operating lifetimes are increased by 9 times more.