Shen Piaoyang, Cao Fan, Wang Haoran, Wei Bin, Wang Feijiu, Sun Xiao Wei, Yang Xuyong
Key Laboratory of Advanced Display and System Applications of Ministry of Education , Shanghai University , 149 Yanchang Road , Shanghai 200072 , China.
Institute of Advanced Energy , Kyoto University , Uji , Kyoto 611-0011 , Japan.
ACS Appl Mater Interfaces. 2019 Jan 9;11(1):1065-1070. doi: 10.1021/acsami.8b18940. Epub 2018 Dec 28.
Despite the rapid development in quantum-dot light-emitting diodes (QD-LEDs) with a single junction, it remains a big challenge to make tandem QD-LEDs with high performance. Here, we report solution-processed double-junction tandem QD-LEDs with a high external quantum efficiency of 42.2% and a high current efficiency of 183.3 cd A, which are comparable to those of the best vacuum-deposited tandem organic LEDs. Such high-efficiency devices are achieved by interface engineering of fully optimized single light-emitting units, which improves carriers' transport/injection balance and suppresses exciton quenching induced by ZnO, and design of an effective interconnecting layer consisting of poly(4-butylphenyl-diphenylamine) (poly-TPD)-mixed poly(9-vinylcarbazole) (PVK)/poly(3,4-ethylenedioxythiophene):polystyrene sulfonate/polyethylenimine ethoxylated-modified ZnO.
尽管单结量子点发光二极管（QD-LED）发展迅速，但制造高性能的串联QD-LED仍然是一个巨大的挑战。在此，我们报道了通过溶液法制备的双结串联QD-LED，其具有42.2%的高外量子效率和183.3 cd/A的高电流效率，与最佳的真空沉积串联有机发光二极管相当。这种高效器件是通过对完全优化的单个发光单元进行界面工程实现的，该工程改善了载流子的传输/注入平衡，并抑制了由ZnO引起的激子猝灭，以及设计了一种由聚（4-丁基苯基-二苯胺）（聚-TPD）混合聚（9-乙烯基咔唑）（PVK）/聚（3,4-乙撑二氧噻吩）：聚苯乙烯磺酸盐/聚乙烯亚胺乙氧基化改性ZnO组成的有效互连层。
