Improving performance of quantum dot light-emitting diodes through PMA-doped PEDOT:PSS hole injection layer

Abstract

Colloidal quantum dot-based light-emitting diodes (QLEDs) have attracted significant attention owing to their facile solution processability and excellent optical properties, making them promising candidates for developing next-generation display technologies. However, their practical application remains limited due to inefficient hole injection, which remains a significant challenge in achieving high stability and commercial viability for solution-processed QLEDs. This work introduces a hybrid hole injection layer (HIL) to realize efficient solution-processed QLEDs. The designed HIL consists of a conductive polymer poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), doped with inorganic additive phosphomolybdic acid. In this design, the anode-HIL interface, engineered by the hybrid HIL, enhanced the hole injections, leading to improved device performance. The optimized hybrid-HIL-based QLEDs displayed a maximum external quantum efficiency of 9.84 % and a power efficiency of 11.55 lm/W, exhibiting a significant improvement compared to conventional PEDOT:PSS-based devices. These results confirmed that the solution-processable hybrid HIL provides a promising alternative for realizing high-performance, solution-processed QLEDs.