Asahi Kasei has collaborate with Nobel winner Hiroshi Amano and his research team at Nagoya University to develop a laser diode that emits deep-ultraviolet light (in wavelength span of UV-C).
Published in the journal Applied Physics Express in October 2019, the UV light emitting laser diode is based on AIN (aluminum nitride) substrate and emits the world’s shortest lasing wavelength at 271.8 nm under pulsed current injection at room temperature.
Whereas previous short-wavelength semiconductor lasers were only achieved down to 336 nm, the current result demonstrate UV-C emission ranging 200–280 nm. It is expected that UV-C semiconductor lasers would be used for disinfection in healthcare, for treating skin conditions such as psoriasis, and for analyzing gases and DNA.
Lasing under current injection in the ultraviolet range was considered challenging because of the extremely high resistance of the material. Key factors in this successful development including employing a specially designed p-side layer to simultaneously realize sufficient light confinement and reduced device resistance and suppressing light scattering loss by using AlN substrate with few defects. In addition, Asahi Kasei managed to combine its thin-film crystal growth technology with the process technology and evaluation technology of Nagoya University’s CIRFE Transformative Electronics Facilities (C-TEFs).
This research result thus holds the key to high-output UV-C solid-state light sources which have long been sought. The team is now conducting advanced joint research to achieve continuous room temperature deep-UV lasing for the development of UV-C semiconductor laser products.
