UV-C (in wavelength of 200-280nm) LED power output has increased to 70-75mW with application extending from disinfection of personal devices to medium-scale sterilization or purification.
UV-C LED output increased from 10mW in 2014 to 50mW in 2016. South Korea-based LG Innotek and Japan-based Dowa Electronics earlier in 2017 unveiled 280nm UV-C LED chips with power output of 70mW and 75mW respectively.
As users in the medical care and biotech sectors are less sensitive to price, prices and profitability for UV-C LED applications are relatively high with strong potential demand,
The Minamata Convention on Mercury, which took effect on August 16, 2017, will restrict use of mercury beginning 2020, and stimulate demand for UV-C LED application to medium-scale water purification, Digitimes Research believes. Metawater, a water purification plant in Japan, has cooperated with Japan-based Nikkiso to develop a purification system based on 1,000 UV-C LED chips each with power output of 30mW, with a daily capacity to treat 2,000 tons of water.
Currently, two types of substrates are used to make UV-C LED epitaxial wafers - aluminum nitride and sapphire, the former being more adopted. UV-C LED chips using aluminum substrates have higher luminous efficiency and longer service life than those using sapphire, but aluminum substrate prices are 1,000 times those for sapphire substrates.
UV-C LED still faces technological barriers, such as in luminous efficiency and yield rates, to replacing 10-20W low-pressure mercury-vapor lamps which are widely used in sterilization currently.
