Submilliwatt operation of AlGaN-based ultraviolet light-emitting diode using short-period alloy superlattice

Over 0.1 mW ultraviolet output was achieved by an AlGaN-based light-emitting diode. To realize a highly conductive and ultraviolet-transparent layer, a short-period alloy superlattice was introduced. The device was fabricated on SiC substrate. Low electric resistivity due to the short-period alloy superlattice and the high thermal conductivity of the SiC substrate enabled large current injection of up to $\text{1.7\hspace{0.17em}}{\mathrm{kA/cm}}^2.$ The emission was monochromatic band-edge emission about 350 nm in wavelength without significant D–A and/or deep emissions.