Effect of plasma treatment on hydrophilic properties of TiO2 thin films

TiO2 films prepared by reactive sputtering technique were treated by Ar, O2 and N2 radio frequency plasma, respectively. The contact angles of water drop on the surface of TiO2 films, which were measured by drop shape analysis, decreased remarkably with plasma treatment for 1 min. With the increasing of plasma treatment time, the contact angles of the samples treated by O2 plasma decreased rapidly to zero degree, while the contact angles of the samples treated by Ar and N2 plasma decreased slowly. The improvement of hydrophilic property is due to the surface etching, ultraviolet radiation and surface oxidation of plasma treatment.