A Comparative Study of Amorphous, Anatase, Rutile, and Mixed Phase TiO2 Films by Mist Chemical Vapor Deposition and Ultraviolet Photodetectors Applications

This paper presents growing amorphous, anatase, rutile, and mixed phases titanium dioxide (TiO2) thin films by mist chemical vapor deposition and post deposition annealing techniques. The annealing temperature affects crystal structures of the TiO2 films significantly. X-ray diffraction and Raman spectra are used to characterize the structures of the TiO2 films. X-ray photoelectron spectroscopy is used to analyze the chemical composition of the TiO2 film. The optical characteristics, including refractive index, extinction coefficient, optical absorption coefficient, and photoluminescence spectrum are measured. Finally, the metal-semiconductor-metal photodetectors are fabricated and their current-voltage, Schottky barrier height, photoresponse characteristics, response time, and detectivity characteristics are investigated. The research results show that these crystal structures of the TiO2 demonstrate their specific advantages in the performance of the photodetectors.