Tailoring the structural and optical properties of HiPIMS TiO2 thin films for photovoltaic applications

Titanium dioxide (TiO 2 ) thin films are deposited onto glass and silicon <100> substrates by high power impulse magnetron sputtering (HiPIMS) at various substrate positions from the substrate-holder center (x = 0, 10, 20 and 30 mm). The structural analysis conducted through XRD and Raman spectroscopy shows that all the films deposited at lower radial distance (x = 0–20 mm) are identified as pure anatase phase of TiO 2 , while those deposited at 30 mm contain a small trace of rutile phase with anatase phase remaining dominant. AFM analysis reveals homogenous surfaces with low values of roughness (2.6–3.8 nm) and a decrease of grain size with the substrate position. The films exhibit high refractive index and large indirect optical band gaps (3.25–3.38 eV). Finally, UV-blocking and antireflection characteristics are studied.