Research of photocatalytic properties in Nb-doped TiO2 transparent conducting films

• Main Authors: Shu-hui Tsai, 蔡淑惠
• Other Authors: Cheng-chung Lee
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/15914161043869830212

碩士 === 國立中央大學 === 光電科學研究所 === 99 === Nb-doped TiO2 (TNO) film is a material with conductivity and photo-catalytic properties. This research includes two parts, first we investigated the electrical and optical characteristics of the TNO films. The second part, we have discussed the photo-catalytic effect. After annealing in vacuum at 370 ℃, the phase of the deposited TNO film with 90W RF power was transited from amorphous to anatase The resistivity is about 1.26×10-3 Ω-cm, Hall mobility is about 1.46 cm2/V-s, and carrier concentration is about 1.89×1021 cm-3, and the ratio of atom number of titanium and niobium is 6.12. The average transmittance is about70% and the absorbance is less than 10% in visible region. The contact angle of TNO films decreased when the irradiation time increased, which implies the surface property of TNO films are changed from hydrophobic to hydrophilic after ultraviolet irradiation. Furthermore, the sheet resistivity of films is rarely changed under ultraviolet irradiating. For different niobium concentration TNO films, the methylene blue solution degradation speed decreased following the sequence of the deposition power, 90W, 95W, 100W, 85W, 80W, which reveals the same tendency of the contact angle measurement. The higher conductivity, the higher mobility of the carries, and the photo-excitation of electron-hole pair spreading to the surface faster for the photocatalytic reaction.