Proposal and Realization of Light-Emitting HEMT With InGaN Quantum Well Inserted

Abstract

GaN-based Micro-LED technology has been intensively applied in high-resolution display and visible light communication (VLC) applications, benefiting from its enhancement of integration density. However, parasitic issues in the heterogeneous integration of GaN-based Micro-LED and its Si-based CMOS driver are one of the main factors limiting the switching speed in display applications and modulation bandwidth in VLC technology at present. This work reports a novel monolithically integrated device of GaN-based light-emitting diode (LED) and high-electron-mobility transistor (HEMT), which is essentially a light-emitting HEMT (LE-HEMT) based on a p-GaN HEMT epitaxy, with p-GaN being retained under the drain electrode and an InGaN quantum well layer inserted between the AlGaN barrier and the intrinsic GaN layer. The influence of gate-source voltage ( ${V} _{\text {GS}}$ ) and applied drain voltage ( ${V} _{\text {DD}}$ ) on the controllability of LE-HEMT is investigated. It exhibits output current up to 303 mA/mm at ${V} _{\text {DD}} =10$ V and ${V} _{\text {GS}} =2$ V. The luminance and light output power (LOP) reach 2680 cd/m2 and 0.16 W/cm2, respectively, being superior to that of LED-HEMT integrated devices based on HEMT-like epitaxial structures from the literature. Besides, it exhibits good switching performances with a turn-on delay of 288 ns and a turn-off delay of $7.2~\mu $ s. This work offers a novel approach to the monolithic integration of light source and its driving transistor based on an HEMT-like epitaxial structure and simplified fabrication processes, providing a pathway for high-resolution display and high-speed VLC applications.