Production of multicharged iron and nitrogen ions and application to enhance photo-catalytic performance in visible light region on TiO2 thin films

Multicharged iron and nitrogen ions have been produced from solid materials in a 2.45 GHz electron cyclotron resonance (ECR) ion source (TAIKO device, Toyama Prefectural University), and also large area TiO2 thin films are individually produced by reactive sputtering in an arched ECR plasma. We normally form the TiO2 thin film (∼100 nm) on the Si(1 0 0) substrates. We measure the X-ray diffraction for characterization of the TiO2 crystallinity and the contact angle of distilled water for estimation of photo-catalytic performance. The crystalline TiO2 thin films are anatase and rutile phases. Fe3+ and N3+ ions were implanted into TiO2 thin films on the Si substrates in order to enhance photo-catalytic performance in visible light region. The maximum efficiency of photo-catalytic performance has been obtained at the dose of about 2 × 1015 cm−2. We compared contact angles of distilled water on the TiO2 by illuminating fluorescent light for four hours before and after implantation. Photo-catalytic performance of the TiO2 thin film in visible light region after implantation is better than that before implantation without deterioration in ultraviolet light region.