Pressure-dependent photoluminescence study of InxGa1−xN

We present the results of pressure-dependent photoluminescence (PL) studies of single-crystal InxGa1−xN (0⩽x<0.15) films grown on top of thick GaN epitaxial layers by metalorganic chemical vapor deposition with sapphire as substrates. PL measurements were performed at 10 K as a function of applied hydrostatic pressure using the diamond-anvil-cell technique. The luminescence emissions from the InxGa1−xN epifilms were found to shift linearly toward higher energy with increasing pressure. By examining the pressure dependence of the PL spectra, the pressure coefficients for the emission structures associated with the direct band gap of InxGa1−xN were determined. The values of the pressure coefficients were found to be 3.9×10−3 eV/kbar for In0.08Ga0.92N and 3.5×10−3 eV/kbar for In0.14Ga0.86N.