Far-UVC emission of polarity-engineered AlGaN MQW using carbon nanotube-based cold cathode electron beam

Far-ultraviolet-C (UVC) light is an efficient and safe germicide because the wavelength band eradicates viruses but is harmless to human cells. In this study, electron-beam-pumped AlGaN emitters have been introduced as an alternative to far-UVC light emitting diodes which are limited by certain drawbacks, such as low conductivity and light absorption of the p-layer and side emission due to polarization at short wavelengths. We demonstrate a highly efficient far-UVC AlGaN emitter using a carbon nanotube-based cold cathode electron beam (C-beam). To maximize light emission, materials were grown via novel in situ lateral polarity engineering epitaxy. The C-beam enables the large-area emission of up to 528 mm2, and the maximum power conversion efficiency is 0.5% at 232 nm.