Strain and photoluminescence characterization of cubic (In,Ga)N films grown on GaAs(001) substrates

Cubic InxGa1−xN films were successfully grown on GaAs(001) substrates by metalorganic chemical-vapor deposition. The values of x content ranging from 0.10 to 0.24 obtained at different growth conditions were measured by double-crystal x-ray diffraction (XRD). The perpendicular and parallel elastic strain of the In0.2Ga0.8N layer, ε⊥=0.4% and ε∥=−0.4% for GaN and ε⊥=0.37% and ε∥=−0.37% for InGaN, respectively, were derived using the XRD measurements. The inhomogeneous strain and the average grain size of the In0.2Ga0.8N/GaN films were also studied by XRD. Photoluminescence spectra were used to measure the optical characterization of the InxGa1−xN thin films with different In composition, and the near-band-edge emission dependence of cubic InxGa1−xN on the x value is nearly linear with In content x⩽0.24.