Investigation on titanium dioxide thin film for opitical sensor application / Mohd Farhan Aizat Mohamed Nawi

Titanium dioxide (Ti02) exists as amorphous phase. It is non-crystalline that lack of repetitive structure and demonstrate structural disorder at the atomic level. For optical sensor application, the TiC>2 thin film is largely influenced by thickness of the film. Hence the thickness of the TiC>2 thin film can influence the ability of the thin film to absorb the light. This thesis investigates the optical properties for optical sensor applications using Sol-Gel spin coating technique. TiC>2 thin film with various numbers of coatings has been successfully prepared. The numbers of coatings TiC>2 thin film are varied at 1 time, 3 times, 5 times 7 times and 9 times. The effects of different numbers of coatings of the TiC>2 thin films are characterized by means of structural, optical properties and electrical properties. The characterizing involved Atomic force microscope (AFM), Field Emission Scanning Electron Microscopy (FESEM), Ultraviolet visible spectroscopy (UVVis) and spectral sensitivity measurement (I-V measurement). For structural properties, 9 times sample gives the highest roughness among the other sample. As for optical properties, it also showed high absorbing light compare to other samples. The electrical properties show current decrement when the numbers of coating increased. The results showed that number of coatings affected the roughness, conductivity and absorbance of light of the TiC>2 thin films. These differences determined the suitable properties of TiC>2 thin film for optical sensor application.