Enhanced electroluminescence of all-inorganic colloidal quantum dot light-emitting diode by optimising the MoO3 intermediate layer

Abstract

The effects of the molybdenum trioxide (MoO3) intermediate layer on the performance of all-inorganic colloidal quantum dot light-emitting diodes (QD-LEDs) with a structure of ITO/MoO3/NiO/QDs/ZnO/Al are explored. MoO3 layers with different thickness were inserted between the indium tin oxide and nickel oxide layer via a thermal evaporation process. The presented results show that an ultrathin ( ∼ 5 nm) MoO3 intermediate layer significantly enhanced the electroluminescence (EL) intensity of the QD-LED, which was more than 100 times higher than the device without the MoO3 layer. It is suggested that the EL enhancement originates from the effectively facilitated injection of holes into quantum dots through the MoO3 intermediate layer. © The Institution of Engineering and Technology 2014.