Effect of Postannealing on Quantum-Dot Light-Emitting Diodes

Electroluminescent quantum-dot light-emitting diodes (QLEDs) are a promising technology for next-generation display applications. Currently, the performance of red- and green-light-emitting QLED devices is close to the standard for industrialization. However, blue-light-emitting QLEDs are lagging behind due to insufficient charge injection. Herein we present a simple postannealing treatment to the QLED devices that leads to a significant enhancement in the device efficiency by approximately 20%. Enhanced charge injection and improved charge balance are revealed as the origin of the boost in the device performance. Additionally, the postannealing process is also proven to be a universal approach for QLEDs with various metal electrodes.