Major Japanese LED manufacturer Nichia has created a high-power deep UV LED that is designed to destroy coronavirus with its irradiation. The company first announced the successful development of this product last year. Going forward, Nichia will be working with other OEMs to incorporate its deep UV LED into various devices and equipment such as air purifiers and air conditioning systems.

The deep UV LED was jointly developed by Nichia and a team of researchers from Tokushima University. According to their study, a UVC LED with a wavelength of 280nm and a radiant flux of 70mW can annihilate 99.99% of coronaviruses on a surface if the irradiation takes place from a distance of 5cm or less and lasts at least 30 seconds. UVC light has been demonstrated to be highly effective for disinfection applications.

A study by Nichia and the Tokushima team reveals that UV light at the wavelength of 265nm has the highest efficacy in destroying coronavirus. However, the light output and operational lifespan of an LED decreases in correlation with the reduction of the wavelength. In the case of a 260nm LED, its lifespan is only 2,000 hours. When developing its deep UV LED, Nichia adjusted the wavelength to 280nm and raised the radiant flux to 70mW (versus the radiant flux of 35mW for a 265nm LED).

As a result, the newly developed product has a virus-killing efficacy that is 1.3 times greater compared with a 265nm LED. Also, the newly developed product has an operational lifespan of around 20,000 hours, or 10 times longer than that of a 265nm LED. All in all, Nichia and the Tokushima team have created a deep UV LED that offers greater durability and better performance than ever before.

▲ Nichia has discovered that the virus-killing efficacy of UV LED increases in correlation with the rise in radiant flux. (Source: Nichia.)

Further experiments proved that Nichia’s deep UV LED has a virus-killing efficacy of 99.99%. When it comes to cleaning and disinfecting one’s hands, the prevalent methods are washing with running water and applying an alcohol-based sanitizer. According to the Nichia-Tokushima study, washing with running water for 15 seconds eliminates 99% of surface pathogens. However, this is an ideal scenario because people do not always wash their hands properly by rubbing, scrubbing, and rinsing their hands under strong flowing water. As for an alcohol-based sanitizer that contains 77-81% ethanol, spraying and applying it on one’s hands for about 30 seconds eliminates 99.99% of surface pathogens. Again, this high level of efficacy assumes that a sufficient amount of sanitizer is being thoroughly applied to all parts of one’s hands. Hence, handwashing and sanitizer are methods that need some time and effort in order to be truly effective.

Conversely, Nichia’s deep UV LED removes 99.99% of surface pathogens on one’s hands by irradiating UVC light from a distance of 5cm for 30 seconds. It is thus a faster and more convenient technological solution for commercial and public venues.