Quantum-dot light-emitting diodes with Fermi-level pinning at the hole-injection/hole-transporting interfaces  

作　　者：Maopeng Xu Desui Chen Jian Lin Xiuyuan Lu Yunzhou Deng Siyu He Xitong Zhu Wangxiao Jin Yizheng Jin 

机构地区：[1]Zhejiang Key Laboratory for Excited-State Materials,State Key Laboratory of Silicon Materials,Department of Chemistry,Zhejiang University,Hangzhou 310027,China [2]School of Materials Science and Engineering,Suzhou University of Science and Technology,Suzhou 215009,China

出　　处：《Nano Research》2022年第8期7453-7459,共7页纳米研究（英文版）

基　　金：the National Natural Science Foundation of China(Nos.91833303,51911530155,91733302,22001187,and 52062019);the Key Research and Development Program of Zhejiang Province(No.2020C01001);the Natural Science Research Foundation of Jiangsu Higher Education Institutions(No.20KJB150032).

摘　　要：Quantum-dot light-emitting diodes(QLEDs)are multilayer electroluminescent devices promising for next-generation display and solid-state-lighting technologies.In the state-of-the-art QLEDs,hole-injection layers(HILs)with high work functions are generally used to achieve efficient hole injection.In these devices,Fermi-level pinning,a phenomenon often observed in heterojunctions involving organic semiconductors,can take place in the hole-injection/hole-transporting interfaces.However,an in-depth understanding of the impacts of Fermi-level pinning at the hole-injection/hole-transporting interfaces on the operation and performance of QLEDs is still lacking.Here,we develop a set of NiOx HILs with controlled work functions of 5.2–5.9 eV to investigate QLEDs with Fermi-level pinning at the hole-injection/hole-transporting interfaces.The results show that despite that Fermi-level pinning induces identical apparent hole-injection barriers,the red QLEDs using HILs with higher work functions show improved efficiency roll-off and better operational stability.Remarkably,the devices using the NiOx HILs with a work function of 5.9 eV demonstrate a peak external quantum efficiency of~18.0%and a long T95 operational lifetime of 8,800 h at 1,000 cd·m^(−2),representing the best-performing QLEDs with inorganic HILs.Our work provides a key design principle for future developments of the hole-injection/hole-transporting interfaces of QLEDs.

关 键 词：quantum-dot light-emitting diodes Fermi-level pinning hole-injection/hole-transporting interfaces work function PERFORMANCE 

分 类 号：TN312.8[电子电信—物理电子学]