KAUST student wins top award for innovative micro-LED technology

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By David Murphy

Zhiyuan Liu, a Ph.D. candidate in the KAUST Advanced Semiconductor Laboratory (ASL) under the supervision of Professor Xiaohang Li, received a Best Student Award at the 14th International Conference on Nitride Semiconductors (ICNS-14).

Held from November 12–17, 2023, in Fukuoka, Japan, ICNS-14 presented high-impact scientific and technological advances in materials, devices and applications based on nitride semiconductors. During the event, in-depth, independent sessions addressed the fundamental physics behind the critical issues in this field.

According to the event organizers, the Best Student Award presented to young scientists who demonstrate outstanding achievements in their paper, including abstract and presentation, and expect to make significant contributions in the nitride semiconductor field. 

Liu’s ICNS-14 oral presentation, "Etching-free pixel definition in InGaN micro-LEDs through selective thermal oxidation method," outlined a KAUST-developed method for fabricating high-performance micro-LEDs. The work was conducted by members of the ASL team supervised by Professor Li.

“It is a deep honor for me to be recognized for the Best Student Award at another top nitride conference like the ICNS,” he noted. “I think this is also a notable recognition of our work from the conference committee.”

Improving micro-LEDs' energy efficiency 

A key focus of Liu’s research is the development of ultrawide-bandgap semiconductor-based material growth, device modeling and fabrication. At present, he is working on the micro and nano-scale size InGaN and AlGaN-based visible and UV light-emitting diodes.

As reported in Liu’s ICNS-14 winning paper, the ASL team used selective thermal oxidation to form micro-LED pixels without using a conventional plasma etching technique. With this technology, the dielectric material effectively protects the areas used to emit light—LED pixels. In contrast, other non-pixel areas are oxidized during the thermal annealing in the air. 

“The research is a world-first report that a selective thermal oxidation method has been applied to micro-LED fabrication,” he emphasized. “The problem [our work] solves is avoiding sidewall damage and defects typically caused by plasma etching, which significantly reduces device efficiency. 

“As a low-cost, low-complexity and energy-efficient device manufacturing method, it dramatically improves current micro-LED performance and display resolution,” Liu concluded.