Growth of indium-rich nanocrystalline indium gallium nitride thin films by modified activated reactive evaporation

Indium-rich InxGa1-xN thin films were prepared on glass substrates by a mixed source modified activated reactive evaporation technique. All the films exhibit hexagonal wurtzite structure preferentially oriented along the c-axis. The band gap values obtained through Urbach fitting of the absorption edge were found to be in good agreement with the values obtained from photoluminescence spectra. The decrease in band gap below 1.9 eV (i.e., for pure InN) for indium-rich films is mainly due to the compensation of BursteinMoss shift due to gallium incorporation into the lattice which is further confirmed from the carrier concentration measurements. © 2011 World Scientific Publishing Company.