Solution-Processed Quantum-Dots Light-Emitting Transistors With Equivalent Efficiency of Light-Emitting Diodes

Light-emitting transistors (LETs) can combine the capability of switching and electroluminescence (EL) in single device. Herein, we demonstrate solution-processed asymmetric quantum-dots’ hybrid LETs (QD-HLETs) with an Sc:In
₂
O
₃
/ZnO heterojunction semiconductor channel and poly (9-vinlycarbazole) (PVK) hole transport layer, which not only enhance the mobility, but also balance the injection of electrons and holes. The red QD-HLETs exhibit outstanding electrical and optical modulation by gate potential, with a field-effect mobility of 2.7 cm
²
V
⁻¹
s
⁻¹
and a maximum brightness of 129 000 cd/m
²
. And a peak external quantum efficiency (EQE) of 18.5% with low roll-off (EQE is 13.2% at a brightness of 129 000 cd/m
²
) and an operational lifetime of more than 3300 h at 100 cd/m
²
are obtained. In addition, the carriers’ injection from Sc:In
₂
O
₃
and ZnO is optimized by modulating the thickness of Sc:In
₂
O
₃
. It provides an alternative approach to markedly improve LETs’ performance and address these open questions for the device physics.