The optical properties of hydrophilic Ti-doped Al2O3 films

• Hydrophilicity of Al2O3:Ti film increased as the fibers in the film became thinner.
• Al2O3:Ti film with a thinner fibrous morphology had a higher optical energy gap.
• Al2O3:Ti film with a thicker fibrous morphology had a higher visible transmission.
• Al2O3:Ti film had higher linear refractive index by increasing RF power.

Ti-doped Al2O3 (Al2O3:Ti) films were prepared by the simultaneous RF magnetron sputtering of Al2O3 and DC magnetron sputtering of Ti. The structure of the Al2O3:Ti film corresponded to Al2O3. Reducing RF power caused the formation of thinner fibers of Al2O3:Ti in the film, favoring the hydrophilicity and increasing the optical energy gap of the deposited film. When a thicker Al2O3:Ti film was deposited at a higher RF power, it contained thicker fibers, and had a lower surface roughness, higher visible transmission and a higher linear refractive index. The Al/Ti atomic ratio significantly affected the hydrophilicity and optical properties of Al2O3:Ti films.