Fabrication and characterization of Si/SiO₂/TiO₂/ZnO heterostructures from sputtered and oxidized Ti-film

The present work reports the fabrication of p-Si/SiO₂ /TiO₂ and p-Si/SiO₂ /TiO₂ /ZnO heterostructures deposited by RF sputtering on p-Si substrate. The structural properties of the heterostructures were characterized by X-ray reflectivity and SIMS depth profiling. The electrical and optical properties of the heterostructures were investigated by I − V, C-V measurements and VIS spectroscopy, respectively. The measurements reveal that I − V characteristics in dark show semiconductor-insulator-semiconductor (SIS) structure properties. The I − V characteristics under illumination exhibit changes with significant increase of photocurrent due to photoassisted tunnelling and injection through SiO₂ /TiO₂ interlayer.