Voltage-Controlled GaN HEMT-LED Devices as Fast-Switching and Dimmable Light Emitters

This letter reports a novel voltage-controlled light emitter with fast switching speed and dimming capability using a monolithically integrated GaN HEMT-LED device. The integrated HEMT-LED device, with a transconductance of 113 mS/mm and large light emitting area (
$450\times 470\,\,\mu \text{m}^{2}$
), exhibits a fast switching speed of 15 MHz. When functioning as an optical transmitter, a data rate of 16.7 Mbit/s was demonstrated. By reducing the duty cycle of the pulsed gate voltage from 100% to 0.1%, the light intensity decreased accordingly, and a linear pulse-width modulation dimming performance with a wide dimming range (0.1%–100%) and high dimming ratio (51 282:1) was achieved.