Deposition of photocatalytic TiO 2 layers by pulse magnetron sputtering and by plasma-activated evaporation

Abstract

Crystalline TiO 2 thin films, especially layers with predominantly anatase phase, exhibit photocatalytic activities resulting in photoinduced hydrophilic, self-cleaning and antifogging properties. In this paper, a comparison of the photocatalytic properties of layers deposited with two different PVD techniques is given. On one hand, a reactive pulse magnetron sputtering (PMS) system has been used to obtain TiO 2 films at dynamic deposition rates from 8 to 50 nm m/min. On the other hand, TiO 2 layers were deposited by reactive electron beam evaporation at very high deposition rates between 500 and 1000 nm m/min. An additional spotless arc discharge (Spotless arc Activated Deposition—SAD process) was used for plasma activation to improve layer properties. Photoinduced hydrophilicity was investigated by measuring the decrease of the water contact angle during UV-A irradiation.