Solution-processed colloidal quantum dot light-emitting diodes (QLED) have attracted many attentions with significant progress in recent years. However, QLED devices still face some challenges. The energy barrier between Cd-base quantum dots (QDs) and commonly used hole transport materials is larger than that between QDs and electron transport materials, which leads to the imbalance of carriers in the light emitting layer (EML) and the low performance of QLED devices. Herein, we report a simple strategy to improve the device performance by doping small molecule transport material 4,4′-cyclohexylidenebis[N,N-bis(p-tolyl)aniline] (TAPC) into red CdSe/ZnS QDs. The optimized red QLED devices with TAPC-doped emissive layer at a ratio of 3.2 wt% achieve 20.0 cd/A of maximum current efficiency, 16.6 lm/W of power efficiency and 15.7% of external quantum efficiency, which is 30%, 58% and 33% higher than the control device. The improved performance of devices can be ascribed to the increase of hole current density, decrease of leakage electrons and more balanced quantity of carriers in EML. This work put forward a viewpoint to improve the performance of QLED devices via doping high hole mobility materials into emission layer.

近年来，溶液处理的胶体量子点发光二极管（QLED）引起了广泛关注，并取得了重大进展。然而，QLED 器件仍然面临一些挑战。Cd基量子点(QDs)与常用空穴传输材料之间的能垒大于QDs与电子传输材料之间的能垒，导致发光层(EML)载流子不平衡，QLED性能低下设备。在此，我们报告了一种通过将小分子传输材料 4,4'-亚环己基双 [N,N-双（对甲苯基）苯胺]（TAPC）掺杂到红色 CdSe/ZnS QD 中来提高器件性能的简单策略。具有 3.2 wt% 比率的 TAPC 掺杂发射层的优化红色 QLED 器件实现了 20.0 cd/A 的最大电流效率、16.6 lm/W 的功率效率和 15。7%的外量子效率，比控制装置提高30%、58%和33%。器件性能的提高可归因于 EML 中空穴电流密度的增加、漏电子的减少和更平衡的载流子数量。这项工作提出了通过在发射层中掺杂高空穴迁移率材料来提高 QLED 器件性能的观点。