83‐4: High‐Performance Inverted Green and Red InP Quantum‐dot Light Emitting Diodes with Robust ZnS Electron Transport Interlayer

QLED has received extensive attention for decades. However, the performance of QLEDs is still far behind compared with OLED. We focused on the development of new electron transport layer (ETL), which is mainly degradation issue in QLED device. For the first time, we introduced a new, highly stable, and low‐mobility ZnS ETL and used as an interlayer between ZnO and QDs layer. Devices optimized using ZnO/ZnS cascaded ETLs have a peak EQE of 10.8%, a peak CE of 37.5 cd/A, and the device lifetime (LT70) is 265 hours at 1000 nits which is almost 2.2 times greater than those of devices without ZnS. The predicted LT50 at 100 nits is 60,255 hours which is the highest lifetime reported up to date. Further improve the device performance, we introduced a mixing of hole transporting material (HTM) in QDs layer. Devices have improved almost 3.8 times in their lifetime.