Synergistic bulk doping and interfacial passivation for highly efficient and stable SnO2-Based quantum dot light-emitting diodes

A synergistic bulk-interface modulation strategy is developed for SnO 2 -based QLEDs. • Ni-doped SnO 2 effectively suppresses oxygen vacancies and regulates electron transport. • ZnCl 2 interlayer passivates interfacial defects and enhances radiative recombination. • The optimized QLED reaches an EQE of 24.3% EQE and a T 95 lifetime of 2325.1 h. Quantum dot light-emitting diodes (QLEDs) often suffer from limited performance due to interfacial defects and imbalanced carrier injection in the electron transport layer (ETL). Here, we present a synergistic strategy that integrates bulk doping and interfacial passivation to enhance device performance. Ni 2+ -doped SnO 2 nanoparticles (NSO) are employed to regulate electron transport and suppress oxygen vacancies within the ETL. As a result, QLEDs based on NSO achieve an external quantum efficiency (EQE) of 16.1%. To further reduce interfacial defects, a ZnCl 2 interlayer is introduced between the ETL and the quantum dot emissive layer. This interlayer effectively passivates defects on interface of SnO 2 and quantum dot. Consequently, the EQE is increasedto 24.3%, and the T 95 operational lifetime (@1000 cd/m 2 ) is 2325.1 h, representing a 2.1-fold improvement. These results demonstrate that combining bulk mobility regulation with interfacial defect passivation is an effective approach for improving electroluminescence performance of SnO 2 -based QLEDs. Download: Download high-res image (233KB) Download: Download full-size image