Interfacial Charge Modulation: An Efficient Strategy for Stable Blue Quantum-Dot Light- Emitting Diodes

摘要

Quantum-dot light-emitting diodes (QLEDs) are proposed as one of the mostpromising candidates for next-generation displays, but their commercialapplication is seriously limited due to the poor performance of blue QLEDs(B-QLEDs). Herein, this work uses Ti_3C_2T_x nanosheets to tune the workfunction (WF) of ZnMgO and to engineer the quantum dot (QD)/electrontransport layer (ETL) interface. The B-QLEDs with ZnMgO-Ti_3C_2T_x hybrid ETLexhibit a maximum EQE of 15.81 and a remarkable T50 operation lifetime of3284 h at 100 cd m~(?2). In addition to that, ultraviolet photoemission spectroscopyand density functional theory calculations both confirm that the additionof Ti_3C_2T_x to ZnMgO can effectively tune the ZnMgO’s work function, furthergive rise to the reduction of QD/ETL energy barrier, which finally results inthe alleviation of charge accumulation at the QD/ETL interface. The findingsof interface engineering by Ti_3C_2T_x not only provide a promising strategy forthe application of 2D materials in optoelectronic devices, but also pave theway to construct high-performance light-emitting diodes.