Optical properties of TiO2 thin films prepared by sol-gel method

Titanium dioxide in the anatase phase has been synthesized by the sol-gel method. Then, the solution was deposited onto glass substrate using spin coating technique. These thin films are then annealed at a temperature ranged from 350°C to 550°C. The optical and topology of the thin film was characterized using UV-VIS and AFM. Based on the readings from UV-VIS spectroscopy, it is found that transmittance properties of TiO₂ thin films increased as the annealing temperatures increased. The UV-VIS results were supported by the AFM. From AFM, it can be observed that as the temperature increase the grain size will also increase. The surface topography of thin films becomes more uniform. The roughness of the surface is also increased and the height variation becomes much larger.