Deep UV-LED expected to be the next-generation light source to replace mercury lamps
In 2014, three Japanese simultaneously received the Nobel Prize in Physics for their study on “blue LEDs”. The “deep UV-LED” attracts attention as a new progressive technology. With a shorter wavelength among ultraviolet rays, deep ultraviolet has strong disinfection effectsand other features. It's expected that deep ultraviolet will be applied to water disinfection and air purification in many fields including medical care and engineering.
“Mercury lamps” have been used for such purposes, but the use of these lamps will be restricted from 2020 based on the Minamata Convention in consideration of harm mercury causes to human body and environment. Deep UV-LED produces very little such detrimental effects and has LED-specific features such as compactness, energy savings, and a long life. It's a “next-generation light source”.
Since 2006, we have been committed to efforts toward the commercialization of deep UV-LED, serving as the engine to drive the industry as a leading company.
Aiming at commercialization of deep UV-LEDs with Nobel Prize winners
We focused attention on deep UV-LEDs in 2006. In those days, it was difficult technically for researchers to put ultraviolet rays into commercial use in the region of shortwaves with a wave length of 365 nm or less. With great expectations on its future potential, we turned to Professor Hiroshi Amano (Nagoya University), who won the Nobel Prize in Physics years later, for guidance. In 2008, we confirmed light emission of deep UV-LEDs for the first time even if it's several tens of μW. Three months later, we succeeded in stable light emission of 1mW.
In 2010, we finally achieved a stable light emission with an external quantum efficiency* of 3% or more, realizing practical performance and quality. While the results of other research institutions and companies were 1% or so, the result broke the previous world record and suddenly attracted the attention of the industry.
- * External quantum efficiency = ratio of light radiated to the outside, light extraction efficiency
Toward commercialization and stable mass production
After realizing commercialization, the next step is to establish a mass production system. In addition to efforts to improve the yield that enables mass production and conduct research in stable quality maintenance, we achieved an external quantum efficiency of 10% or more. In 2014, we established the long-awaited “Hakusan Factory” (Hakusan City in Ishikawa Prefecture), thereby preparing the initial mass production organization. It was in 2015 that we succeeded in the commercialization of deep UV-LEDs that achieved both a light output of 30 mW and a useful life of 10,000 hours or more, as the first case in the world.
Currently, we develop and offer deep UV-LED water disinfection modules capable of large-capacity water disinfection and deep UV-LED purification systems for aquaculture. As an “equipment manufacturer” we are committed to contribute to society by creating unprecedented and completely new products while focusing on new technology development.