Short-wavelength UV LEDs with higher output are likely to be used increasingly in applications such as disinfecting water, sterilizing surfaces, and spectroscopy. Crystal IS, Inc., a manufacturer of ultraviolet LEDs for monitoring, purification, and disinfection applications, has reported a UV-C LED with an optical output of 65mW at 260 nm when operated in continuous mode.
UV-C refers to ultraviolet light with wavelengths of 200-280 nm. Light in the UV-C wavelength range can be used for disinfecting water, sterilizing surfaces, destroying harmful micro-organisms in food products and in air, and for spectroscopy applications.
Leo Schowalter, founder and CTO of Cystal IS, described the latest results as “a technological milestone in the continued development of brighter, more efficient and reliable UV-C LEDs. By employing die thinning and encapsulation techniques, we were able to increase the photon extraction efficiency to over 15%,” he said.
Details were recently published in Applied Physics Express. “By fabricating our LEDs on our home-grown aluminum nitride (AlN) substrates, we continue to set the pace of what is possible for the combination of highest efficiencies and longest lifetimes in the 250-280 nm wavelength range, far surpassing diodes fabricated on sapphire,” added Schowalter.
Yole Développement estimates that the UV-C lamp market was nearly $200 million in 2012, with lamps being replaced increasingly by UV LEDs.
"Our products will address some of the most pressing health concerns of our time,” said Therese Jordan, senior VP of business development. “We are seeing demand in both water and air for the disinfection and quality-monitoring aspects of UV-C. Similarly, spectroscopic instruments are also taking advantage of the high light output available in a UV-C LED.
“Unlike UV lamps, UV-C LEDs are mercury-free, compact, rugged and robust, lending themselves to an array of designs. They hold the promise of long life and environmentally friendly end-of-life disposal.”
