230 nm electron-beam excited light source with AlGaN/AlN multiple quantum wells on face-to-face annealed sputter-deposited AlN template

We conducted a comprehensive investigation into the optimal architecture of light-emitting devices operating in the 230 nm wavelength band, which were fabricated face-to-face by annealing sputter-deposited AlN templates for electron-beam excitation. The structures and multiple quantum wells were systematically optimized. The present findings revealed that employing AlN as the underlayer and the barrier layers produced significant improvements in surface smoothness and enhanced cathodoluminescence intensity. Moreover, the optimized device was successfully integrated with a graphene-based electron source, facilitating light emission through electron-beam excitation and achieving a power efficiency of 0.16 %. Remarkably, this power efficiency remained stable with increasing injected current from the graphene-based electron source, demonstrating a linear increase in light output without the efficiency droop associated with conventional light-emitting diodes. These results validate the potential of a simplified device structure that eliminates the need for a p-type layer, aiding the development of large-area, high-output light sources within the 230 nm band.