Publication
Far-UVC light sources in the spectral range of200-230 nm effectively kill bacteria and deactivate viruses while being not harmful to health, enabling persistent disinfection of air and surfaces in the presence of humans. So far only excimer lamps have been a unique viable solution in this narrow UV spectral range. Those light sources are commercially available but suffer from EMC compatibility issues and fundamental limitations on size-reduction potential. Far-UVC AlGaN light emitting diodes (LEDs) with wavelengths below 250 nm exhibit exponential collapse of external quantum efficiency (EQE) well below 1% [1]. Only recently, deep-UV LEDs with AlGaN/AlGaN quantum wells (QWs) with an emission at 226 nm were demonstrated with 0.28% EQE and 0.18% wall plug efficiency (WPE) [2], but the device lifetime is limited to ~10 h [2].