Far-UVC Solid-State Lamps – FUSSL

Common UV sources used for disinfection emit in the 254-270 nm range. This radiation is highly carcinogenic and cataractogenic, which represents a health hazard. Recently, it has been demonstrated that far-UVC emission in the 220-230 nm range can efficiently inactivate pathogens without harm for humans, since it cannot penetrate the outer (non-living) layers of human skin or eyes. The standard way to obtain such far-UVC emission is through high-frequency discharge KrCl excimer lamps. There is no solid-state alternative, and LEDs face intrinsic transport issues that limit their efficiency in that spectral range. The target of FUSSL is to develop a new generation of mercury-free, 100% recyclable, efficient, high-brightness solid-state lamps operating in the 220-230 nm spectral range. Such devices are based on electron beam pumping of AlGaN nanostructures. FUSSL will exploit the enhanced radiative efficiency that results from carrier confinement in nanometer-scale localization centers (atomic layer thickness fluctuations, alloy inhomogeneities or quantum dots), and boost the light extraction efficiency by nano-patterning. Carrier injection will be performed using cold field emission sources based on carbon nanotubes (CNTs) or nano-patterned pyrolytic sheets. We target an output power of 1 W, with a power efficiency of 5%, i.e. about 50 times higher than current LED technologies in this spectral range.