Stable and Efficient Pure Blue Quantum Dot LEDs Enabled by Inserting an Anti-oxidation Layer

Here, we propose inserting an anti-oxidation layer (PBO (Poly-p-phenylene benzobisoxazole)) between the HTL and QD layer, which takes in some accumulated holes from HTL and mitigates the oxidation-induced damage to the HTL, enabling a record T50 operational lifetime of more than 41000 h with an initial brightness of 100 cd m-2 in pure blue QD-LEDs (emitting at 458 nm). Meanwhile, it facilitates hole injection and helps reduce electron leakage, allowing a record peak external quantum efficiency (EQE) of up to 23%.