Effects of Pulsed Negative Bias and Current Density on Properties of N-Doped TiO<sub>2</sub> Films Deposited by Arc Ion Plating

Abstract

The N-doped TiO2thin films of different pulsed negative bias and different current density were deposited on medical glass slide by arc ion plating. The influence of pulsed substrate bias and arc current on film properties was investigated by varying pulsed negative biases from 0 V to−600V and arc current from 40A to 60A. Film structure, surface morphologies and optical properties were measured with XRD, SEM and UV-VIS transmittance spectroscope. Photo-catalytic performance of the films was evaluated by degrading methyl orange. The results show that the N-doped TiO2films absorption edge successfully moved to 550nm and the films had better visible light response. Applying the negative pulse bias extended the absorption edge 5 nm - 40 nm, the absorption edge shifted towards the visible region with increasing arc current. The annealing treatment had a great impact on extending the absorption edge of the lower arc current, and the best extending can increase 64nm after annealing. The film surface roughness decreased with the increase of pulse negative bias, and the film surface grain size increased significantly after annealing. The N-doped TiO2film not only reduced the UV catalytic performance, but also extended its catalytic properties to the sun light.