Heteroepitaxial growth of wurtzite InN films on Si„111... exhibiting strong near-infrared photoluminescence at room temperature

High-quality InN epitaxial films have been grown by nitrogen-plasma-assisted molecular-beam epitaxy on Si~111! substrates using a double-buffer technique. Growth of a ~0001!-oriented single crystalline wurtzite–InN layer was confirmed by reflection high-energy electron diffraction, x-ray diffraction, and Raman scattering. At room temperature, these films exhibited strong near-infrared ~0.6–0.9 eV! photoluminescence ~PL!. In addition to the optical absorption measurement of absorption edge and direct band nature, the PL signal was found to depend linearly on the excitation laser intensity over a wide intensity range. These results indicate that the observed PL is due to the emission of direct band-to-band recombination rather than the band-to-defect ~or impurity! deep emission. © 2004 American Institute of Physics. @DOI: 10.1063/1.1738183#