Strain effects on the intersubband transitions in GaN/AlN multiple quantum wells grown by low-temperature metal organic vapor phase epitaxy with AlGaN interlayer

The strain in low-temperature-grown GaN/AlN multiple quantum wells (MQWs) have been tailored by inserting an AlGaN interlayer between an AlN template and the MQWs, for the purpose of intersubband transition (ISBT) at shorter wavelength (1.52 mu m) with smaller full-width at half-maximum (FWHM) (113 meV). The strain in GaN wells, ISBT wavelength and its FWHM were dependent on Al-content in the AlGaN interlayer. The compressive strain in GaN wells shifted ISBT to shorter wavelengths and narrowed absorption peaks. The interlayer with an appropriate Al-content has been proved to be mandatory for achieving strong and short-wavelength ISBT by metal organic vapor phase epitaxy-grown GaN/ AlN MQWs. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3253715]