Influence of GaN underlayer thickness on structural, electrical and optical properties of InN films grown by PAMBE

► InN thin films were grown on c-Al2O3 substrates and on GaN films by PAMBE. ► InN films were characterized by HRXRD, Hall measurements, absorption and Raman spectroscopy. ► The optical band gap of InN films was found to be carrier concentrations dependent. ► The dependence of optical band gap on carrier concentration was described using k.p model.