Room-temperature deep-ultraviolet-stimulated emission Al(x)Ga(1-x)N thin films grown on sapphire

Abstract

Room-temperature deep-ultraviolet-stimulated emission (SE) has been observed from optically pumped metalorganic chemical vapor deposition grown Al(x)Ga(1-x)N thin films. SE has been observed for Al concentrations as high as x = 0.26, with a resultant SE wavelength as low as 328 nm at room temperature. The results obtained for the Al(x)Ga(1-x)N layers are compared with In(x)Ga(1-x)N layers of comparable alloy concentration and GaN reference layers. The incorporation of Al into GaN is shown to result in Al(x)Ga(1-x)N layers with similar high excitation-density emission behavior as GaN, in contrast to In(x)Ga(1-x)N layers, which exhibit markedly different SE behavior. The observation of room-temperature SE from Al(x)Ga(1-x)N layers of significant Al concentration illustrates the suitability of Al(x)Ga(1-x)N based structures, not only for use in deep-ultraviolet detectors, but also as a potential source of deep-ultraviolet laser radiation. (C) 1999 American Institute of Physics. [S0003-6951(99)02702-3].