RF sputter deposition of amorphous TiOx films: role of deposition time

Titanium oxide thin films were synthesized using the radio frequency (RF) sputtering technique at varying deposition times ranging from 50 to 125 min. The fabricated films display an amorphous character, with the predominant chemical state of titanium being Ti4+, accompanied by a minor proportion of Ti3+ states. The optical absorption edges shifted to longer wavelengths, increasing from 288 to 293 nm, as the deposition time increased. The optical band gap (Eg) was indirect and decreased from 3.911 to 3.762 eV. The refractive index and dispersion parameters were evaluated and analyzed.