Fully Multi-Functional GaN-based Micro-LEDs for 2500 PPI Micro-displays, Temperature Sensing, Light Energy Harvesting, and Light Detection

GaN-based Micro-LEDs were developed for more than a decade and are considered as the next generation of display technology. Micro-LEDs have more versatile functions than displays. We report fully multi-functional Micro-LEDs for micro-displays, temperature sensing, light energy harvesting, and light detection. The 2500 pixel per inch (PPI) Micro-LED devices displayed animations and pictures in display mode driven by a Si complementary metal-oxide-semiconductor (CMOS) backplane. In temperature sensing mode, it showed a sufficient linearity with a resolution of 795 K/V. It also had a fill factor of 65.9% and efficiency of 15.5% in light energy harvesting mode and a sensitivity of 1240 and external quantum efficiency (EQE) of 33% in light detection mode. Results real that the proposed devices can be used as a self-sustainable micro-system for low cost and eco-friendly applications.