Optical properties of InN rods on sapphire grown by metal–organic chemical vapor deposition

The InN rods were grown by metal–organic chemical vapor deposition with a density of 1.4×109 cm−2. Optical properties of InN rods have been systematically investigated by means of temperature dependent photoluminescence (PL) and power dependent PL. Four peaks appear in the PL spectra and the origination was analyzed. The lowest energy peak P1 (0.665 eV) is attributed to transitions of conduction band electrons to the photo-holes captured by deep acceptor; P2 (0.717 eV) is the direct band-to-band transition peak of InN; main peak P3 (0.759 eV) results from the recombination of degenerate electrons with photo-holes near the top of the valence band (Burstein–Moss effects); the high energy shoulder P4 (0.787 eV) was by the co-effect of quantum confinement and the Burstein–Moss effects due to the small size distribution of InN wetting layers.