• Continuous operation at room temperature, an important milestone in semiconductor laser development, in the deep-ultraviolet region
• Successful fabrication of laser diode with crystal dislocation completely suppressed, reducing drive power to 1/10 of that previously required
• Represents a major step toward commercialization by enabling battery-powered operation

In a joint research project, Asahi Kasei and a research group led by Professor Hiroshi Amano of the Center for Integrated Research of Future Electronics, Institute of Materials and Systems for Sustainability, Nagoya University, have achieved the world's first continuous room-temperature operation of a semiconductor laser diode (LD) in the deep-ultraviolet (UVC) region, at 274 nm.

In 2019, the same project achieved the world's shortest semiconductor lasing wavelength under pulsed current injection at room temperature.¹ The result announced today represents a major step forward toward practical application.

The researchers found that crystal defects in earlier devices degraded the laser characteristics, preventing continuous operation. They succeeded in suppressing the defects, which enabled drive power to be reduced to 1/10 and achieved continuous operation which could be powered by a battery.

Applications of the UVC LD are expected to include disinfection and therapeutic applications, detection and measurement of viruses and particulates, gas analysis, and precise laser processing of metals, carbon materials, and resins.

Zhang Ziyi, an Asahi Kasei researcher in the project, commented, “I wanted to do something new. Everyone assumed that the deep ultraviolet laser diode was an impossibility, but Professor Amano told me, 'We have made it to the blue laser, now is the time for ultraviolet.' Its application to sterilization technology could be groundbreaking. Unlike the current LED sterilization methods, which are time-inefficient, lasers can disinfect large areas in a short time and over long distances.”

The successful results have been reported in two papers in Applied Physics Letters as below.

Title

Key temperature-dependent characteristics of AlGaN-based UV-C laser diode and demonstration of room-temperature continuous-wave lasing

Authors

Ziyi Zhang, Maki Kushimoto, Akira Yoshikawa, Koji Aoto, Chiaki Sasaoka, Leo J. Schowalter, and Hiroshi Amano

DOI

10.1063/5.0124480 (to be published online on November 28, 2022)

Title

Local stress control to suppress dislocation generation for pseudomorphically grown AlGaN UV-C laser diodes

Authors

Maki Kushimoto, Ziyi Zhang, Akira Yoshikawa, Koji Aoto, Yoshio Honda, Chiaki Sasaoka, Leo J. Schowalter, and Hiroshi Amano

DOI

10.1063/5.0124512 (to be published online on November 28, 2022)

News