Characteristics of quantum-dot light-emitting diodes fabricated using a sputtered zinc tin oxide electron-transporting layer

Abstract

Quantum-dot light-emitting diodes (QD-LEDs) with a sputtered zinc tin oxide (ZTO) electron-transporting layer (ETL) were studied. A ZTO after-deposition treatment process consisting of oxygen plasma treatment and thermal annealing was studied to improve the performance of the sputtered metal oxide ETL. The optical and electrical properties of the ZTO ETL could be controlled by adjusting the thermal annealing temperature. The best performing QD-LED was obtained by applying the oxygen plasma treatment and 250 degrees C thermal annealing in N-2 atmosphere in sequence. The relation between the ZTO ETL properties and the device performance was explained by considering the roles of the band gap defect states. In this work, we provide a way to control the ZTO ETL properties and to improve the QD-LED device performance by applying an after-deposition treatment to the ZTO ETL. (C) 2018 The Japan Society of Applied Physics