Effects of oxygen partial pressure and substrate temperature on the structure and optical properties of Mg_xZn_1−xO thin films prepared by magnetron sputtering

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• 作者：Xinghua Zhang^a ; Zunming Lu^a ; Fanbin Meng^a ; Yongzhong Wang^a ; Ying Li^a ; Xiao Yu^a ; Chengchun Tang ; ^a ; ^{xinghua146@yahoo.com.cn}
• 关键词：Magnetron sputtering ; Transmission ; Band gap ; Photoluminescence
• 刊名：Applied Surface Science
• 出版年：2011
• 出版时间：15 May 2011
• 年：2011
• 卷：257
• 期：15
• 页码：6554-6559
• 全文大小：589 K

文摘

Deposited with different oxygen partial pressures and substrate temperatures, Mg_xZn_1−xO thin films were prepared using a Mg_0.6Zn_0.4O ceramic target by magnetron sputtering. The structural and optical properties of the prepared thin films were investigated. The X-ray diffraction spectra reveal that all the films on quartz substrate are grown along (2 0 0) orientation with cubic structure. The lattice constant decreases and the crystallite size increases with the increase of substrate temperature. Both energy dispersive X-ray spectroscopy and calculated results suggest the ratio of Mg/Zn increases with increasing substrate temperature. The thin film deposited with T_s = 500 °C has a minimal rms roughness of 7.37 nm. The transmittance of all the films is higher than 85 % in the visual region. The optical band gap is not sensitive to the oxygen partial pressure, while it increases from 5.63 eV for T_s = 100 °C to 5.95 eV for T_s = 700 °C. In addition, the refractive indices calculated from transmission spectra are sensitive to the substrate temperature. The photoluminescence spectra of Mg_xZn_1−xO thin films excited by 330 nm ultraviolet light indicate that the peak intensity of the spectra is influenced by the oxygen partial pressure and substrate temperature.