| AVS 57th International Symposium & Exhibition | |
| Thin Film | Thursday Sessions |
| Session TF-ThP |
| Session: | Thin Film Poster Session II |
| Presenter: | H.A. Shukur, Kogakuin University, Japan |
| Authors: | H.A. Shukur, Kogakuin University, Japan I. Takano, Kogakuin University, Japan |
| Correspondent: | Click to Email |
Titanium dioxide (TiO2) has considerable properties such as photocatalytic effect, dye-sensitized photovoltaic effect, photoinduced hydrophilicity and transparent electrod. Among all these properties photocatalytic property has been interested by many researchers because of its promised application such as antifouling effect and ability to decompose environmental pollution materials. However, TiO2 has a high band gap (3.0 ~ 3.2 eV) so that the most photocatalytic effect occurs under UV irradiation. In order to improve TiO2 behavior under visible light, there is many researchers have used various methods such as gas or metal doping.
In this study N+ ion implantation was used to improve the optical properties of TiO2 films, which were prepared by reactive magnetron sputtering on glass substrate (corning #1737). The substrate was sputtered by Ar ions in order to clean the surface before the TiO2 thin film formation. Titanium (Ti) was sputtered from Ti target in an Ar / O2 gas and the substrate was hated at 200 oC. The total film thickness was around 145nm with a deposition rate of 0.025nm/sec. N+ ion was irradiated to TiO2 thin film at 15keV in acceleration voltage and 40µA/cm2 in ion current density with a various irradiation doses from 2.5×1015 to 250×1015ions/cm2. Film thickness of the samples was measured by Avantes optical spectrometers system (AvaSpe-2048). The structure was determined by X-ray diffraction (XRD: MAC Science High quality XG M18XCE) with CuKα (0.154nm) radiation at an incident angle of 0.3º, and the composition was characterized by X-ray photoelectron spectroscopy. The photocataylitic property was measured by a methylene blue immersion test. The spectrophotometer (SHIMADZU UV-2550) was used to measure the difference in light absorption at a wave length of 665nm and also was used to measure the optical band gap for ion irradiated films.
N+ ion implanted TiO2 films showed a narrower optical band gap than unirradiation films, i.e. N+ was substituted for O and created a new energy level. Optical band gap was changed from 3.58 to 3.5 eV at sample of 12.51015ions/cm2 ion irradiation dose, this sample was showed a maximum photocatalytic activity for visible light.