Growth temperature induced physical property variation of InN films grown on nitrided sapphire substrate by PAMBE

• InN epilayers were deposited on nitrided sapphire substrates by plasma-assisted MBE.
• The growth temperature is critical to influence the physical properties of the InN films.
• The quality of InN layers presented significant improvements with the proper growth temperature.

InN epilayers were deposited on nitrided sapphire substrates using plasma-assisted molecular beam epitaxy (PAMBE) system. The physical properties of InN films under different growth temperatures were thoroughly studied. The XRD results indicated that as-prepared InN films without Indium droplets were preferentially oriented in the c-axis direction. The SEM results showed that the InN films grown in a two-dimensional mode with a thickness of ∼200 nm under the growth temperature of 460 °C. In addition, the optical absorption measurement exhibited that the energy bandgap of InN films was around 0.75–0.81eV and the PL spectra of the epilayers revealed an infrared emission. Moreover, the electrical properties of the films were discussed by Hall effect in detail.