The purest 520! We’re giving you perovskite QLED with the highest EQE efficiency!

　　Owing to their outstanding color purity, perovskite quantum-dot–based light-emitting diodes (QLEDs) hold great promise for future solid-state lighting and high-definition displays. However, charge imbalance during device operation can lead to charge accumulation, which in turn causes luminescence quenching and degrades device performance. Researchers led by Song Jizhong at Nanjing University of Science and Technology have reported a green-light perovskite QLED that exhibits high color purity as well as high efficiency and long-term stability.

　　Researchers have achieved charge injection balance by employing a dual-electron-transport-layer architecture, thereby enhancing both EQE efficiency and device lifetime. The charge-balanced QLED exhibits a saturated green emission, with an EL spectral full width at half maximum (FWHM) of only 18 nm and a fluorescence peak at 520 nm.

　　The device exhibits a turn-on voltage of only 2.0 V, and its peak external quantum efficiency (EQE) reaches 21.63%, making it the most efficient perovskite QLED reported to date. Furthermore, compared with the control device, the charge-balanced device demonstrates an almost 20-fold increase in operational lifetime, with a T50 lifetime of up to 180 hours—representing the best stability among all currently reported perovskite LEDs. These results indicate that, through rational structural engineering, the performance of perovskite QLEDs can be optimized for practical applications in lighting and displays.