Novel GaN-based ultraviolet optoelectronics for optical wireless communication and maskless photolithography

We present a portfolio of novel GaN-based ultraviolet optoelectronic devices that enable reconfigurable optical wireless communication and compact maskless photolithography. A three-terminal GaN diode with an integrated gate terminal enables tunable emission and bias-tee-free modulation, boosting communication bandwidth by 64% and enabling optoelectronic NAND/NOR logic operations. Further miniaturization leads to a 25μm AlGaN-based dual-functional diode achieving record performance: 585 MHz optical bandwidth, 300 mA/W responsivity, and a 3.7ns rise time. This supports simultaneous high-efficiency light emission and high-speed detection within a single footprint. Finally, a vertically integrated micro-LED array with a backside photodetector through a transparent sapphire substrate enables a self-stabilized emission system with real-time optical feedback, demonstrated in a stable and compact deep-UV maskless photolithography setup. Together, these devices advance GaN-based ultraviolet optoelectronics for next-generation communication and lithographic technologies.