Abstract: Ta-doped ZnO films were deposited under different substrate temperatures using radio frequency magnetron sputtering . The effects of the substrate temperature on the component , microstructure , morphology , and the optical properties of the films were investigated by energy dispersive spectrometer (EDS), X-ray diffractometer (XRD), scanning electron microscope (SEM), ultraviolet-visible (UV-vis) spectrophotometer, photoluminescence (PL) spectrometer.EDS results verify that Ta elements have been doped into the ZnO films successfully .XRD patterns results show that the structures of the prepared films maintain the hexagonal wurtzite of ZnO and are not influenced by the Ta element as the substitutional impurities .The (002) diffraction peak intensity of Ta-doped ZnO film first increases and then decreases with the increase of substrate temperature .It reaches the maximum value at the substrate temperature of 400 ℃.SEM results show the grain size of the Ta-doped ZnO film becomes bigger when the substrate temperature is increased to 400 ℃ and 500 ℃.UV-vis spectra indicate that the average transmittance of the Ta-doped ZnO film is higher than 80;and the Ta-doped ZnO film deposited without heating the substrate possesses the highest transmittance in visible light range .The band gap energy of Ta-doped ZnO film extracted from the absorption edge of transmission spectra is in the range of 3.34~3. 37 eV.The minimum band gap energy of 3.34 eV is obtained for the Ta-doped ZnO films deposited at the substrate temperature of 500 ℃.PL spectra verified that the Ta-doped ZnO film deposited at 500 ℃have more defects , which can also explain the reduction of the band gap energy .

Key words: Ta-doped ZnO films were deposited under different substrate temperatures using radio frequency magnetron sputtering . The effects of the substrate temperature on the component , microstructure , morphology , and the optical properties of the films were investigated by energy dispersive spectrometer (EDS), X-ray diffractometer (XRD), scanning electron microscope (SEM), ultraviolet-visible (UV-vis) spectrophotometer, photoluminescence (PL) spectrometer.EDS results verify that Ta elements have been doped into the ZnO films successfully .XRD patterns results show that the structures of the prepared films maintain the hexagonal wurtzite of ZnO and are not influenced by the Ta element as the substitutional impurities .The (002) diffraction peak intensity of Ta-doped ZnO film first increases and then decreases with the increase of substrate temperature .It reaches the maximum value at the substrate temperature of 400 ℃.SEM results show the grain size of the Ta-doped ZnO film becomes bigger when the substrate temperature is increased to 400 ℃ and 500 ℃.UV-vis spectra indicate that the average transmittance of the Ta-doped ZnO film is higher than 80;and the Ta-doped ZnO film deposited without heating the substrate possesses the highest transmittance in visible light range .The band gap energy of Ta-doped ZnO film extracted from the absorption edge of transmission spectra is in the range of 3.34~3. 37 eV.The minimum band gap energy of 3.34 eV is obtained for the Ta-doped ZnO films deposited at the substrate temperature of 500 ℃.PL spectra verified that the Ta-doped ZnO film deposited at 500 ℃have more defects , which can also explain the reduction of the band gap energy .