Optical investigations on Si-doped InN films

We report a detailed study of the optical properties unintentionally doped and n‐doped InN films grown by Metal Organic Vapour Phase Epitaxy. When increasing the doping, a blue‐shift of the absorption and reflectance spectra is found that we quantitatively correlate with the doping. Our measurements give us the value of the two‐band Kane model parameter: 12 eV and an asymptotic value for the InN band gap at 300 K: 1160 meV. Moss‐Burstein shift and band gap renormalization effects are computed as well as a non‐parabolic effective mass. This is found to equal 0.09 m0 in the unintentionally doped case. The photoluminescence spectra are strongly redshifted with respect to the bandgap and are always peaking near 760 meV. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)