Structural and optical properties of zinc oxide thin films prepared by spray pyrolysis method
Structural and optical properties of zinc oxide thin films prepared by spray pyrolysis method
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喷雾热解法制备氧化锌薄膜的结构和光学性能
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
Y. Ufuktepe
中科院分区：
文献类型：
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作者：
C. Gumus;O. M. Ozkendir;H. Kavak;Y. Ufuktepe
以空气和醋酸锌溶液为载气，在400 °C的温度下，采用喷雾热解法在玻璃衬底上制备了ZnO多晶薄膜。采用包络法从紫外-可见-近红外（UV-VIS-NIR）区的透射光谱中测定了样品的折射率n和消光系数k等光学常数。薄膜在可见光区表现出高透过率（> 90%）、低吸收率和低反射率。由透射光谱的干涉计算了薄膜的吸收系数α和厚度t。薄膜的能带隙和厚度分别为3.27 eV和0.31-0.52 μ m。用x射线衍射仪分析了薄膜的晶体结构。薄膜是多晶的性质与优选的（002）垂直于基板表面的取向和晶粒尺寸估计为40 nm。采用实空间光电子多重散射方法，对ZnO薄膜中Zn的K边以上区域进行了扩展X射线吸收精细结构（EXAFS）计算。对于ZnO薄膜，从EXAFS光谱得到的最近邻原子的相关均方相对位移的值显示出良好的一致性，从X射线衍射实验测量。
Polycrystalline ZnO thin films were deposited on a glass substrate by a spray pyrolysis technique using solution of zinc acetate and air as the carrier gas at 400 °C temperature. Optical constants such as refractive index n and extinction coefficient k, were determined from transmittance spectrum in the ultraviolet-visible-near infrared (UV-VIS-NIR) regions using envelope methods. The films were found to exhibit high transmittance (>90 %), low absorbance and low reflectance in the visible regions. Absorption coefficient a, and the thickness of the film t were calculated from interference of transmittance spectra. The energy band gap, and the thickness of the films were evaluated as 3.27 eV and 0.31-0.52 pm respectively. The crystallographic structure of these films was analyzed with x-ray diffractometer. The films were polycrystalline in nature with preferred (002) orientation perpendicular to substrate surface and the grain size estimated to be 40 nm. The extended x-ray absorption fine structure (EXAFS) calculations above the K-edge of Zn in the ZnO thin film have been performed by using real-space multiple scattering of photoelectrons. For ZnO thin films, the values of the correlated mean square relative displacements of nearest-neighbor atoms derived from EXAFS spectra show good agreement with those measured from the x-ray diffraction experiments.