Stokes Shift and Band Gap Bowing in $In_xGa_{1-x}N$ (0.060 ≤ x ≤ 0.105) Grown by Metalorganic Vapour Phase Epitaxy

We presented the results of electrical and optical studies of the properties of $In_xGa_{1-x}N$ epitaxial layers (0.060≤x≤0.105) grown by metalorganic vapour phase epitaxy. Resistivity and Hall effect measurements of the samples were carried out at room temperature. Optical properties of the samples were characterized by photoluminescence and optical absorption spectroscopy. The comparison between the photoluminescence and the optical absorption measurements gives the Stokes shift. We explained the observed Stokes shift in terms of Burstein-Moss effect. The band gap versus composition plot for $In_xGa_{1-x}N$ alloys is well fitted with a bowing parameter of≈3.6 eV.