Enhanced current efficiency in top-emitting organic light-emitting diodes using a novel Mg:Ag/Ag cathode structure

Top-emitting organic light-emitting diodes (TEOLEDs) are crucial for modern displays due to their high contrast, energy efficiency, and flexibility. However, developing an optimized transparent cathode remains challenging due to trade-offs between optical transparency, electrical conductivity, and electron injection efficiency. This study introduces a novel Mg:Ag/Ag cathode structure, combining a 1 nm Mg:Ag layer with a 9 nm Ag layer. This design ensures minimal optical losses, and enhanced electron injection while maintaining high conductivity. Comprehensive characterization reveals that the Mg:Ag/Ag cathode outperforms conventional Mg:Ag cathodes, achieving a transmission coefficient of 0 . 55 ± 0 . 04 , sheet resistance of 14 . 6 Ω / □ , and a modified Haacke figure of merit (FoM) of 0 . 42 ± 0 . 04 . TEOLED devices with the Mg:Ag/Ag cathode exhibit a 10-fold increase in power efficiency ( 107 lm/W vs. 11 lm/W ). These results underscore the potential of the Mg:Ag/Ag cathode for next-generation flexible and transparent OLED displays. This work provides a significant advancement in cathode design, offering a promising solution for high-performance, energy-efficient, and durable organic electronic devices.