Role of annealing environment and partial pressure on structure and optical performance of TiO2 thin films fabricated by RF sputter method

Abstract

Influences of the different annealing ambient (in air, 1 bar, 2 bar, 3 bar and 4 bar oxygen partial pressure) on the titanium dioxide (TiO2) thin films deposited on soda lime glass by standard radio frequency (RF) magnetron reactive sputtering method at 100 W were investigated by means of X-ray diffractometer (XRD), ultra violet spectrometer (UV-vis), and Scanning Electron Microscopy (SEM). It was found that either optical properties or energy band gaps of the films enhanced with increase in the oxygen partial pressure up to 3 bar. The energy band gaps of the films (except for the film annealed in 4 bar oxygen partial pressure) became larger than the film annealed in atmospheric pressure. The best transmission was observed for the thin film annealed in 3 bar oxygen partial pressure. Moreover, not only was grain-like structure found to be more dominant than dot-like structure but also growth of anatase phase was observed instead of that of the rutile phase with increasing oxygen partial pressure up to 3 bar. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim