Effects of annealing on properties of ZnO thin films prepared by electrochemical deposition in chloride medium
Effects of annealing on properties of ZnO thin films prepared by electrochemical deposition in chloride medium
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DOI：
10.1016/j.apsusc.2009.10.032
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发表时间：
2010-01-01
影响因子：
6.7
通讯作者：
Heinrich, H.
中科院分区：
文献类型：
--
作者：
Lupan, O.;Pauporte, T.;Heinrich, H.
开发高质量氧化锌薄膜的低成本低温合成技术对于ZnO基光电器件的制造至关重要，特别是紫外（UV）发光二极管，激光器和探测器。我们表明，在室温下观察到的性质，特别是紫外线发射，电沉积ZnO薄膜从氯化物介质（在70摄氏度）上的氟掺杂的氧化锡（FTO）衬底是强烈的影响，生长后的热退火处理。X射线衍射（XRD）分析表明，薄膜沿沿着（0 0 2）方向择优生长。在150-400摄氏度的温度范围内，在空气中的热退火已经进行了这些ZnO薄膜。所生长的膜含有氯，其在400摄氏度退火后被部分去除。退火后的形态变化进行了讨论，在组成薄膜的ZnO晶体中观察到的组成变化。在我们的实验中，由于缺陷水平和氯含量的降低，ZnO薄膜的光学质量在150 ° C和400 ° C的沉积后热处理后得到改善。透射谱和吸收谱变陡，光学带隙红移到单晶值。这些研究结果表明，电沉积具有潜在的高品质的ZnO薄膜的生长与器件应用的缺陷减少。(C)2009年爱思唯尔B。V.保留所有权利。
The development of cost-effective and low-temperature synthesis techniques for the growth of high-quality zinc oxide thin films is paramount for fabrication of ZnO-based optoelectronic devices, especially ultraviolet (UV)-light-emitting diodes, lasers and detectors. We demonstrate that the properties, especially UV emission, observed at room temperature, of electrodeposited ZnO thin films from chloride medium (at 70 degrees C) on fluor-doped tin oxide (FTO) substrates is strongly influenced by the post-growth thermal annealing treatments. X-ray diffraction (XRD) measurements show that the films have preferably grown along (0 0 2) direction. Thermal annealing in the temperature range of 150-400 degrees C in air has been carried out for these ZnO thin films. The as-grown films contain chlorine which is partially removed after annealing at 400 degrees C. Morphological changes upon annealing are discussed in the light of compositional changes observed in the ZnO crystals that constitute the film. The optical quality of ZnO thin films was improved after post-deposition thermal treatment at 150 degrees C and 400 degrees C in our experiments due to the reducing of defects levels and of chlorine content. The transmission and absorption spectra become steeper and the optical bandgap red shifted to the single-crystal value. These findings demonstrate that electrodeposition have potential for the growth of high-quality ZnO thin films with reduced defects for device applications. (C) 2009 Elsevier B. V. All rights reserved.