Efficient Quantum-Dot Light-Emitting Diodes With 4,4,4-Tris(N-Carbazolyl)-Triphenylamine (TcTa) Electron-Blocking Layer

4,4,4-tris(N-carbazolyl)-triphenylamine (TcTa) with low electron mobility are used as electron-blocking layer (EBL) for quantum-dot light-emitting diodes (QD-LEDs). With TcTa EBL, electrons are effectively blocked, while holes are efficiently injected; consequently, the developed QD-LEDs exhibit significantly improved performance. Maximum external quantum efficiency of 5% and maximum luminance of 16710 cd/m2are achieved, which represent a 2.7-fold and a 2-fold improvement, respectively, compared with those of the devices without TcTa EBL.