针对量子点发光二极管空穴传输层和电子传输层的迁移率差异而导致的电荷不平衡问题,将具有最低未占分子轨道高能级的有机聚合物Spiro-OMeTAD薄膜放置在空穴传输层与量子点发光层之间,阻挡过剩电子由量子点发光层向空穴传输层的传输,促进器件的电荷平衡,制备出一种高效的新型绿色量子点发光二极管。结果表明:相比于传统器件,新型绿色量子点发光二极管器件的外部量子效率提升了87%,达到11.87%,亮度提升了106%,达到53055 cd/m ²;阻挡过剩电子的传输可以显著改善器件中的电荷不平衡现象。

A charge imbalance often occurs in quantum dot light-emitting diodes (QLEDs) owing to the difference in migration rate between the hole transport layer (HTL) and the electron transport layer. In this study, we inserted a Spiro-OMeTAD thin film, an organic polymer with a high lowest unoccupied molecular orbital energy level, between the HTL and quantum dot emission layer to block the transmission of excess electrons from the quantum dot luminescence layer to the HTL, which promotes the charge balance of the device, and thus a highly efficient new green QLED is fabricated. The results show that the new green QLED exhibits distinct improvements over the traditional devices, with an 87% improvement in external quantum efficiency up to 11.87%, and a 106% increase in brightness up to 53055 cd/m 2. This proves that blocking the transmission of excess electrons can significantly solve the charge imbalance problem in QLEDs.