Publication Date:
2012-04-15
Description:
In this article, nanocrystalline anatase TiO 2 films were prepared using a powerful hydrothermal technique and characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopic (XPS), and UV–vis absorption spectra. A metal–semiconductor–metal ultraviolet (UV) detector based on TiO 2 films with Au electrodes was fabricated. The photoelectron properties of the TiO 2 films, including current–voltage (I–V) curves under UV illumination, spectral response and response time were studied in detail. The results of the experiment demonstrate that the crystallinity of the TiO 2 film was greatly improved by the hydrothermal technique: the atom ratio between Ti and O on the surface of TiO 2 film is calculated to be 1.87:1, which indicates that the obtained TiO 2 film has less oxygen vacancies. The improved crystallinity as well as the correspondingly decreased hole trap concentrations finally resulted in a short photoresponse decay time of 4.183 s. Meanwhile, a responsivity of 56.5 mA/W, a low dark current of 5.95 nA, a UV photo-to-dark current ratio of 10 3 were also obtained for the TiO 2 -based detector, all of which suggest that the fabricated TiO 2 films are very promising in UV detection applications.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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