Effect of N-Doping on Absorption and Luminescence of Anatase TiO₂ Films

Anatase TiO₂ films are deposited on glass substrates at different oxygen partial pressures of 0.8–1.6 Pa. Room temperature N ion implantation is conducted in the films at ion fluences up to 5×10¹⁷ ions/cm². UV−visible absorption and photoluminescence (PL) are investigated. With the increase of N ion fluences, the band gap of TiO₂ decreases and the absorbance increases. X-ray photoelectron spectroscopy (XPS) confirms the formation of O-Ti-N nitride after implantation, resulting in the red shift of the band gap. The PL intensity of the deposited films increases with the increasing oxygen partial pressure and decreases remarkably due to the irradiation defects induced by ion implantation.