A monolithically integrated GaN light-emitting transistor with multifunctional electro-optical modulation and high current gain

A GaN-based light-emitting transistor (LET) with electro-optical conversion capability is proposed, in which a vertical LED is vertically integrated on a bipolar junction transistor (BJT) within the same epitaxial wafer. This approach dramatically lowers driving power consumption, eliminates the parasitic effects of conventional bonding techniques, and greatly increases integration density and current transport capability. It offers a novel way to realize high-resolution, high-efficiency Micro-LED displays and intelligent optoelectronic integrated systems due to its significantly simplified driving circuitry, efficient suppression of parasitic effects, and notable improvement of current gain and response speed. In addition to combining photodetection, current amplification, and electroluminescence into one device, the proposed LET device allows independent dual-mode modulation using ultraviolet (UV) light and base current. With a responsivity of 0.53 A/W, the LET device demonstrates a good photoresponse. Furthermore, the device exhibits an exceptional electrical and optical on/off ratio on the order of 10 5 It achieves a maximum current gain of 55, one of the highest values among known comparable integrated devices. The LET has high-speed dynamic modulation capability up to 100 kHz, stable logic operation, and effective UV-responsive switching. The development of Micro-LED is greatly aided by these outstanding performances, which allow the device to incorporate effective photodetection, signal amplification, and light emission capabilities. The LET epitaxial structure's base region quality could be further optimized to increase the device's current gain.