Highly efficient and stable hybrid quantum-dot light-emitting field-effect transistors

Abstract

Light-emitting field-effect transistors (LETs) have drawn much attention for their special capability of combining switching and electroluminescence capacity in a single device. Herein, we report a colour-saturated, high-efficiency red quantum-dot hybrid light-emitting field-effect transistor (QD-HLET) with a solution-processed InScO/ZnO-nanoparticle heterojunction channel layer and a deep-level organic hole transport layer (HLT). The red QD-HLET exhibits a field-effect mobility of 3.1 cm² V⁻¹ s⁻¹ with an on/off ratio of ∼10⁵, a maximum brightness of 145 000 cd m⁻² with a peak external quantum efficiency (EQE) of 22.8% and low efficiency roll-off (an EQE of 17.0% at a brightness of 100 000 cd m⁻²). In addition, the operating stability of the HLET is investigated by monitoring the time-dependent change in the brightness of the QD-HLET under various V_GS, while an operational lifetime of more than 153 000 hours at 100 cd m⁻² is achieved. A comprehensive study on the electrical and optical characteristics of the red QD-HLET under different operation modes is conducted, and an operation model is proposed.