Highly efficient transparent quantum-dot light-emitting diodes based on inorganic double electron-transport layers

Herein, we report the fabrication of high-performance transparent quantum-dot light-emitting diodes (Tr-QLEDs) with ZnO/ZnMgO inorganic double electron-transport layers (ETLs). The ETLs effectively suppress the excess electron injection and facilitate charge balance in the Tr-QLEDs. The thick ETLs as buffer layers can also withstand the plasma-induced damage during the indium tin oxide sputtering. These factors collectively contribute to the development of Tr-QLEDs with improved performance. As a result, our Tr-QLEDs with double ETLs exhibited a high transmittance of 82% at 550 nm and a record external quantum efficiency of 11.8%, which is 1.27 times higher than that of the devices with pure ZnO ETL. These results indicate that the developed ZnO/ZnMgO inorganic double ETLs could offer promising solutions for realizing high-efficiency Tr-QLEDs for next-generation display devices.