Performance Improvement of Single-Component White Quantum Dot Light-Emitting Diodes Enabled by an Insulating Passivation Interlayer

Abstract

In this work, solution-processed single-component white quantum dot light-emitting diodes (WQLEDs) were demonstrated by using the zinc oxide quantum dots (ZnO-QDs) as both a white fluorescent emitter as well as an effective electron injection layer. Meanwhile, a thin insulating passivation layer of polystyrene (PS) was inserted between the ZnO-QDs layer and aluminum cathode to optimize the electron injection into the device and reduce the non-radiative recombination at the interface between ZnO-QDs layer and cathode. Consequently, the WQLEDs with such an insulating PS interlayer exhibit a high brightness of 1076 cd/m2, showing a great improvement of~40% compared with that of WQLEDs without PS passivation interlayer (780 cd/m2). This work provides an efficient method to realize single component WQLEDs, thus bringing a feasible solution for next-generation solid-state lighting technologies.

Keywords: White quantum dot light-emitting diodes, zinc oxide quantum dots, single-component, insulating passivation interlayer