Temperature-controlled epitaxy of InxGa1-xN alloys and their band gap bowing

InxGa1-xN alloys (0 <= x <= 1) have been grown on GaN/sapphire templates by molecular beam epitaxy. Growth temperature controlled epitaxy was proposed to modulate the In composition so that each InxGa1-xN layer was grown at a temperature as high as possible and thus their crystalline quality was improved. The bandgap energies of the InxGa1-xN alloys have been precisely evaluated by optical transmission spectroscopy, where the effect of residual strain and electron concentration (the Burstein-Moss effect) on the bandgap energy shift has been considered. Finally, a bowing parameter of similar to 1.9 +/- 0.1 eV has been obtained by the well fitting In-composition dependent bandgap energy. (C) 2011 American Institute of Physics. [doi:10.1063/1.3668111]