Cu ion beam induced effects and phase study of vanadium oxide thin films

The present work is focused on the optical properties and phase transitions in vanadium oxide thin film due to copper ion irradiation. The deposition of VO2 thin films on Si substrates was carried out in the range of less than 100 nm thickness, by magnetron sputtering. The tandem accelerator facility at National Centre for Physics, Islamabad was used to irradiate the VO2 thin films by 5 MeV Cu ion with variable doses of 1 × 1015, 5 × 1015, 1 × 1016 ions/cm2. The structural properties were studied by the x-ray diffraction and the phase changes from tetragonal to monoclinic were observed. The band gap measurements were carried by diffused reflectance spectroscopy (DRS) and surface morphology by high resolution AFM. The AFM results show variant grain size and surfaces roughness with respect to the induced irradiation doses. The smooth surface was observed at comparatively higher dose of the irradiation. The results confirm the excellent optical and electrical properties of vanadium oxide thin films for the application as a smart functional material.