Kim Bada, Lee Dohyeong, Hwang Boram, Eun Yebin, Ha Mi-Young, Kim Chang Kyo
Department of Electronic Materials and Devices Engineering, Soonchunhyang University, Asan, Chungnam 31538, Republic of Korea.
Display New Technology Institute, Soonchunhyang University, Asan, Chungnam 31538, Republic of Korea.
J Nanosci Nanotechnol. 2021 Jul 1;21(7):3747-3752. doi: 10.1166/jnn.2021.19230.
In this paper, we reported superior performance of solution-processed top-emission quantum dot light-emitting diodes (TE-QLEDs) with Mg-doped ZnO nanoparticle (NP) electron transport layer (ETL). The Mg-doped ZnO NPs were synthesized by the sol-gel method. Transmission electron microscopy (TEM) analysis of the Mg-doped ZnO NPs with 0 wt%, 5 wt%, 10 wt%, and 15 wt% Mg-doping concentrations revealed average diameters of 5.86 nm, 5.33 nm, 4.52 nm, and 4.37 nm, respectively. The maximum luminance, the current efficiency, and external quantum efficiency (EQE) were 178,561.8 cd/m², 56.0 cd/A, and 14.43%, respectively. However, for the best performance of TE-QLED without Mg-doping in the ZnO NPs, the maximum luminance was only 101,523.4 cd/m², the luminous efficiency was 27.8 cd/A, and the EQE was 6.91%. The improvement of the performance is attributed to the suppression of electron transfer by an increase in the energy barrier between the cathode and Mg-doped ZnO NP ETL and the reduction in the Hall mobility of electron with increasing the Mg-doping in the ZnO NPs, resulting in the enhanced charge balance in the quantum dot (QD) emitting layer (EML).
在本文中，我们报道了采用掺镁氧化锌纳米颗粒（NP）电子传输层（ETL）的溶液法制备的顶部发射量子点发光二极管（TE-QLED）的卓越性能。掺镁氧化锌纳米颗粒通过溶胶-凝胶法合成。对掺镁浓度分别为0 wt%、5 wt%、10 wt%和15 wt%的掺镁氧化锌纳米颗粒进行透射电子显微镜（TEM）分析，结果显示其平均直径分别为5.86 nm、5.33 nm、4.52 nm和4.37 nm。最大亮度、电流效率和外量子效率（EQE）分别为178,561.8 cd/m²、56.0 cd/A和14.43%。然而，对于氧化锌纳米颗粒中未掺镁的TE-QLED的最佳性能，最大亮度仅为101,523.4 cd/m²，发光效率为27.8 cd/A，EQE为6.91%。性能的提高归因于阴极与掺镁氧化锌纳米颗粒ETL之间的能垒增加抑制了电子转移，以及随着氧化锌纳米颗粒中掺镁量的增加电子的霍尔迁移率降低，从而导致量子点（QD）发光层（EML）中电荷平衡增强。
