Full-color nano-LEDs for better, longer lasting LED performance

Prof. Zetian Mi and his team earned the Society for Information Display’s Distinguished Paper Award for their research on developing multicolor, single nanowire LEDs. These LEDs can improve high-resolution imaging and displays, lighting, communications, sensing, and medical diagnostics. Specifically, they can support high-resolution display technologies like VR headsets and Google Glass. They could also be capable of delivering invisible ultraviolet-spectrum light that has been proven effective in water and air purification and sterilization of medical equipment.

“At first, we focused on individual nanowires where we could control the image and color by just changing the diameter of the nanowires,” says ECE postdoctoral researcher Xianhe Liu, who was lead author on the paper. “By assembling the nanowires into an array, we were able to achieve multicolored emission, which can support three-dimensional projection displays, flexible displays, and even virtual retinal display technologies.”

These nano-LEDs and their resulting structures are integrated on a single chip and grown in a single process step using selective growth. This boosts efficiency and performance while lowering costs—bridging a gap that has historically limited LED use in numerous markets. The previous GaN-based LEDs were bright, stable, and efficient, but were not capable of multicolor emissions. However, InGaN nanowire structure makes it possible to achieve multicolor emission on one substrate

“InGaN nanowire structure allows us to meet the next generation requirements,” Liu says.

The U-M startup NS Nanotech, co-founded by Mi, is working on bringing this technology to market. The micro-LEDs were fabricated using the Lurie Nanofabrication Facility (LNF). The paper is “Submicron full-color LED pixels for microdisplays and micro-LED main displays.”