Room-temperature deep-ultraviolet-stimulated emission from AlxGa1−xN thin films grown on sapphire

Abstract

Room-temperature deep-ultraviolet-stimulated emission (SE) has been observed from optically pumped metalorganic chemical vapor deposition grown ${\mathrm{Al}}_x{\mathrm{Ga}}_{\text{1−x}}\mathrm{N}$ thin films. SE has been observed for Al concentrations as high as $\text{x=0.26,}$ with a resultant SE wavelength as low as 328 nm at room temperature. The results obtained for the ${\mathrm{Al}}_x{\mathrm{Ga}}_{\text{1−x}}\mathrm{N}$ layers are compared with ${\mathrm{In}}_x{\mathrm{Ga}}_{\text{1−x}}\mathrm{N}$ layers of comparable alloy concentration and GaN reference layers. The incorporation of Al into GaN is shown to result in ${\mathrm{Al}}_x{\mathrm{Ga}}_{\text{1−x}}\mathrm{N}$ layers with similar high excitation-density emission behavior as GaN, in contrast to ${\mathrm{In}}_x{\mathrm{Ga}}_{\text{1−x}}\mathrm{N}$ layers, which exhibit markedly different SE behavior. The observation of room-temperature SE from ${\mathrm{Al}}_x{\mathrm{Ga}}_{\text{1−x}}\mathrm{N}$ layers of significant Al concentration illustrates the suitability of ${\mathrm{Al}}_x{\mathrm{Ga}}_{\text{1−x}}\mathrm{N}$ based structures, not only for use in deep-ultraviolet detectors, but also as a potential source of deep-ultraviolet laser radiation.