Preparation of AlN thin film and the impacts of AlN buffer layer on the carrier transport properties of p-NiO/n-InN heterojunction by magnetron sputtering

Abstract

The aluminum nitride (AlN) films were deposited on Al2O3 substrates at different nitrogen flow rates by radio frequency (RF) magnetron sputtering. The X-ray Diffraction (XRD) patterns indicated that the obtained AlN film exhibited significant (110) and (100) diffraction when the nitrogen flow rate was 4 sccm. The analysis of surface morphology by scanning electron microscope (SEM) showed that the surface morphology of AlN films had a transition from nanoparticles to long nanorods as the nitrogen flow rate was increased. Moreover, the optical transmittance of AlN films was decreased with the increase of nitrogen flow rates and the band gap energy varied from 4.48 to 5.58 eV. Afterwards, the prepared AlN film was used as a buffer layer to insert in the p-NiO/n-InN device, and the improvements of the buffer layer on transport behaviors of the device were studied. Furthermore, the device was placed in 30–110 °C to analyze the effect of temperature on the carrier transport mechanism. Finally, the long-term stability of the unpackaged device was also investigated, and the reasons for the deterioration of the device characteristics were analyzed.