Hwang Youngjun, Jung Hyeonwoo, Kim Jongyoun, Lee Dongwoo, Lee Youngu
Department of Energy Science & Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 333, Techno Jungang Daero, Hyeonpung-Eup, Dalseong-Gun, Daegu, 42988, Republic of Korea.
Small. 2025 Sep;21(36):e04867. doi: 10.1002/smll.202504867. Epub 2025 Jul 17.
The intrinsic degradation of quantum dot light-emitting diodes (QLEDs) is often attributed to the insufficient stability of hole transport materials (HTMs), which adversely affects both efficiency and operational lifetime. Despite efforts to address this issue, HTMs with high bond dissociation energy (BDE) for enhanced QLED performance remain underdeveloped. Here, a series of dibenzofuran (DBF)-incorporated HTMs with high BDE is synthesized to improve QLED efficiency and longevity. Among them, poly(9,9-dioctylfluorene-co-N,N-diphenyldibenzo[b,d]furan-1-amine) (1-PFDBF) exhibits superior hole mobility, high BDE, extended exciton lifetime, and reduced trap density. Green QLEDs employing 1-PFDBF achieve a maximum external quantum efficiency (EQE) of 25.71%, a maximum current efficiency of 102.98 cd A⁻¹, and a maximum power efficiency of 75.69 lmW⁻¹, significantly outperforming poly(9,9-dioctyl-fluorene-co-N-(4-butylphenyl)diphenylamine) (TFB)-based QLEDs. Notably, the EQE of 1-PFDBF-based green QLEDs ranks among the highest for devices utilizing triarylamine-based HTMs. Furthermore, the operational half-lifetime of the 1-PFDBF-based QLEDs is ≈15 900 h at 1 000 cd m⁻ and ≈1 460 000 h at 100 cd m⁻, making a significant increase of 3 600% and 6 600%, respectively, compared to TFB-based QLEDs. These findings establish DBF incorporation as an effective strategy for enhancing HTM BDE and hole mobility, optimizing charge balance within QLEDs, and ultimately enabling high-efficiency and long-lasting QLEDs.
量子点发光二极管（QLED）的本征降解通常归因于空穴传输材料（HTM）稳定性不足，这对效率和工作寿命均产生不利影响。尽管人们努力解决这一问题，但具有高键解离能（BDE）以提高QLED性能的HTM仍未得到充分发展。在此，合成了一系列具有高BDE的含二苯并呋喃（DBF）的HTM，以提高QLED的效率和寿命。其中，聚（9,9-二辛基芴-co-N,N-二苯基二苯并[b,d]呋喃-1-胺）（1-PFDBF）表现出优异的空穴迁移率、高BDE、延长的激子寿命和降低的陷阱密度。采用1-PFDBF的绿色QLED实现了25.71%的最大外量子效率（EQE）、102.98 cd A⁻¹的最大电流效率和75.69 lmW⁻¹的最大功率效率，显著优于基于聚（9,9-二辛基芴-co-N-（4-丁基苯基）二苯胺）（TFB）的QLED。值得注意的是，基于1-PFDBF的绿色QLED的EQE在使用基于三芳基胺的HTM的器件中名列前茅。此外，基于1-PFDBF的QLED在1000 cd m⁻时的工作半衰期约为15900小时，在100 cd m⁻时约为1460000小时，与基于TFB的QLED相比，分别显著提高了3600%和6600%。这些发现表明，引入DBF是提高HTM的BDE和空穴迁移率、优化QLED内电荷平衡并最终实现高效且持久的QLED的有效策略。
