| Ultraviolet (UV) detectors have attracted intense in recent years because of military and civil value. Recently, many wide-band-gap semiconductors with good optical properties such as doped GaN and ZnO have been used for UV detectors. Titanium dioxide (TiO2) has been widely investigated for solar cell, photocatalyst, because they have good physical and chemical properties, especially optical properties. TiO2 is a wide band gap (Eg=3.2eV) semiconductor that can be used for ultraviolet detectors. In this paper, UV detectors used of TiO2 thin films is fabricated. In order to extend the range of sensing spectra, a new kind of material that exhibits the same material advantages as pure TiO2 is wanted. It's optical band gap can be turned by varying the composition, just like AlxGa1-xN and MgxZn1-xO. In this thesis, TiO2 thin films were prepared by sol-gel method. Influence of different calcinations temperatures on the structural and optical properties of samples was researched. TiO2 UV detectors with MSM structure were fabricated. In addition, MnxTi1-xO2, SrxTi1-xO2,LaxTi1-xO2,NdxTi1-xO2 thin films were prepared. Their structures were investigated by X-ray diffraction (XRD) and atomic force microscopy (AFM). Optical properties of the films were examined by UV obsorption spectra. TiO2 thin films were prepared at various calcinations temperatures by sol-gel process. The XRD results showed that TiO2 thin film was anatase phase at 350-750℃, and further into rutile phase at 850℃. As the calcinations temperature increases, the TiO2 crystallites continue to grow. In optical spctra of samples calcined at 650,750,850℃, strong obsorbances were observed in UV region. Moreover, there is a gradual shift of obsorbance edge towards the longer wavelength region. TiO2 UV detector was firstly reported. The response potocurrent (PC) as a function of waveltngth for detector was measured. The OC spectrum showed an cut-off edge at around 360nm. The response photocurrent is very large in the range of 280 to 230nm. MnxTi1-xO2 thin films with different x were prepared at different calcination temperatures by sol-gel method. The XRD results indicate that Mn0.1Ti0.9O2 thin films was antase and rutil phase at 550℃. Mn0.2Ti0.8O2 thin films obtained with calcination temperatures as low as 550℃ were pure rutile, while TiO2 thin films calcined at 550℃ were anatase. Mn0.2Ti0.8O2 thin films present lower surface roughness than TiO2 thin films. As the calcinations temperature increases, the intensity of antase decreases and the intensity of rutile increases. Peaks of anatase were not observed at 750℃. For Mn0.2Ti0.8O2 ,Mn0.33Ti0.67O2, Mn0.5Ti0.5O2 thin films, peaks of anatase were not obserbed at 450℃. Influence of calcinations temperatures on optical properties of MnxTi1-xO2 thin films was studied. As the calcinations temperature increases, absorption edge red-shifted. Then influene of the Mn composition on optical properties of samples was researched. Absorption edges of MnxTi1-xO2 thin films shifted towards longer wavelengths than that of TiO2. Larger Mn composition, the absorption edge wavelength is longer. The results indicated that the range of sensing spectra extend towards longer wavelength by increasing calcinations temperatures and the Mn composition. Then SrxTi1-xO2 thin films with different x were prepared at different calcinations temperature by sol-gel method. The XRD results indicate that SrxTi1-xO2 thin films have the similar structural properties to TiO2, when x is less than 0.3. Their optical properties were studies by UV obsorption spectra. Absorption edges of SrxTi1-xO2 thin films shifted towards shorter wavelengths than that of TiO2. The results indicated that the range of sensing spectra extend towards shorter wavelength by inducting Sr. In additin, LaxTi1-xO2 thin films and NdxTi1-xO2 thin films were prepared. However, the XRD and UV obsorption spectra did not present good results. That proved that LaxTi1-xO2 thin films and NdxTi1-xO2 thin films were not suitable for Ultra...
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