Zhang Tong, Chang Zongming, Wu Yixian, Zhou Mingming, Zhou Boyu, Jiang Yuhan, Wang Yanping
School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, People's Republic of China.
Engineering Research Center of Optoelectronic Functional Materials, Ministry of Education, Changchun 130022, People's Republic of China.
J Phys Chem Lett. 2025 Sep 18;16(37):9785-9790. doi: 10.1021/acs.jpclett.5c02394. Epub 2025 Sep 10.
Inverted quantum dot light-emitting diodes (QLEDs) show great promise for next-generation displays due to their compatibility with integrated circuit architectures. However, their development has been hindered by inefficient exciton utilization and charge transport imbalance. Here, we present a strategy for regulating charge-exciton dynamics through the rational design of a multifunctional hole transport layer (HTL), incorporating polyethylenimine ethoxylated (PEIE) as a protective interlayer in fully-solution-processed inverted red QLEDs. This HTL comprises poly[(9,9-dioctylfluorenyl-2,7-diyl)--(4,4'-(-(4-butylphenyl)] (TFB) doped with iridium(III) bis(2-methyldibenzo[,]quinoxaline) acetylacetonate (Ir(MDQ)(acac)) and performs three critical functions: facilitating Förster resonance energy transfer to quantum dots, enabling Coulomb-assisted hole injection, and suppressing nonradiative recombination. The optimized inverted red QLEDs at a 5 wt % Ir(MDQ)(acac) doping concentration achieved a record external quantum efficiency (EQE) of approximately 24.5% and an operational lifetime () exceeding 24,600 h at 100 cd m. This work establishes fundamental design principles for high-performance inverted QLEDs, highlighting the crucial role of charge-exciton management in advancing optoelectronic device performance.
