On the Effect of Thin Film Growth Mechanisms on the Specular Reflectance of Aluminium Thin Films Deposited via Filtered Cathodic Vacuum Arc
On the Effect of Thin Film Growth Mechanisms on the Specular Reflectance of Aluminium Thin Films Deposited via Filtered Cathodic Vacuum Arc
复制标题
薄膜生长机制对过滤阴极真空电弧沉积铝薄膜镜面反射率的影响
作者：
G. Rincón;I. Heras;Elena Guillén Rodríguez;E. Schumann;M. Krause;R. Escobar
太阳能集热器镜面反射率的优化是提高聚光太阳能发电（CSP）工厂全球产量的关键参数。本文研究了过滤阴极真空弧沉积参数，特别是工作压力和沉积时间对铝薄膜镜面反射率和漫反射率的影响。镜面反射率的变化，通过紫外-可见和近红外光谱（UV-vis-NIR）分光光度法测量，直接与薄膜元素浓度的深度分布，卢瑟福背散射光谱（RBS），表面和横截面的形态，通过扫描电子显微镜（SEM）和轮廓测量。最后，原子力显微镜（AFM）提供的信息的粗糙度和薄膜的生长机制。两个贡献的薄膜的总反射率，即漫反射和镜面反射，被发现是深受沉积条件的影响。实验证明，工作压力和沉积时间直接决定了沉积的主导因素。镜面反射率变化从12到99.8%的总反射率的薄膜生长在相同的工作压力为0.1 Pa，并与不同的沉积时间。这种转变不能归因于RBS所述的膜的氧化，但与沉积时间内样品的粗糙度、表面和本体形态的渐进修改相关。因此，薄膜最终光学性质的演变是由不同的生长机制和由此产生的微结构驱动的。除了最初提出的CSP应用的潜力开发的铝膜的其他应用，而不是CSP，例如，光谱漫反射测量的参考材料，也进行了讨论。
The optimisation of the specular reflectance of solar collectors is a key parameter to increase the global yield of concentrated solar power (CSP) plants. In this work, the influence of filtered cathodic vacuum arc deposition parameters, particularly working pressure and deposition time, on the specular and diffuse reflectance of aluminium thin films, was studied. Changes in specular reflectance, measured by ultraviolet–visible and near-infrared spectroscopy (UV-vis-NIR) spectrophotometry, were directly correlated with thin film elemental concentration depth profiles, obtained by Rutherford backscattering spectrometry (RBS), and surface and cross-sectional morphologies as measured by scanning electron microscopy (SEM) and profilometry. Finally, atomic force microscopy (AFM) provided information on the roughness and growth mechanism of the films. The two contributions to the total reflectance of the films, namely diffuse and specular reflectance, were found to be deeply influenced by deposition conditions. It was proven that working pressure and deposition time directly determine the predominant factor. Specular reflectance varied from 12 to 99.8% of the total reflectance for films grown at the same working pressure of 0.1 Pa and with different deposition times. This transformation could not be attributed to an oxidation of the films as stated by RBS, but was correlated with a progressive modification of the roughness, surface, and bulk morphology of the samples over the deposition time. Hence, the evolution in the final optical properties of the films is driven by different growth mechanisms and the resulting microstructures. In addition to the originally addressed CSP applications the potential of the developed aluminium films for other application rather than CSP, such as, for example, reference material for spectroscopic diffuse reflectance measurements, is also discussed.
影响因子：
5.4
作者：
Fenker, Martin;Balzer, Martin;Kappl, Herbert
通讯作者：
Kappl, Herbert