Keshavarz Hedayati Mehdi, Abdelaziz Moheb, Etrich Christoph, Homaeigohar Shahin, Rockstuhl Carsten, Elbahri Mady
Nanochemistry and Nanoengineering, Institute for Materials Science, Faculty of Engineering, Christian-Albrechts-Universität zu Kiel, Kiel 24143, Germany.
Institute of Condensed Matter Theory and Optics, Abbe Center of Photonics, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, Jena 07743, Germany.
Materials (Basel). 2016 Jul 28;9(8):636. doi: 10.3390/ma9080636.
We report on the fabrication, the characterization, and the optical simulation of a gold-silica nanocomposite and present its integration into a broadband anti-reflective coating (ARC) for a silicon substrate. The two-layer ARC consists of a nanocomposite (randomly distributed gold cluster in a silica matrix) and a pure silica film. We capitalize on the large refractive index of the composite to impose an abrupt phase change at the interface of the coating to diminish the light reflection from the substrate through the ultrathin nanocoating. The average reflectivity of the silicon can be reduced by such a coating to less than 0.1% in the entire visible spectrum. We experimentally and numerically prove that percolated nanocomposites with an overall thickness of 20 nm can provide anti-reflectivity up to near infrared (NIR). The ARC bandwidth can be shifted more than 500 nm and broadened to cover even the NIR wavelength by changing the volume filling fraction of the gold clusters. The angular sensitivity of thin ultrathin antireflective coating is negligible up to 60°. The present ARC could find applications in thermo-photovoltaics and bolometers.
我们报告了一种金-二氧化硅纳米复合材料的制备、表征及光学模拟，并展示了其集成到硅基衬底的宽带抗反射涂层（ARC）中的情况。双层ARC由一种纳米复合材料（二氧化硅基质中随机分布的金簇）和一层纯二氧化硅薄膜组成。我们利用复合材料的高折射率在涂层界面处施加突然的相变，以通过超薄纳米涂层减少从衬底反射的光。通过这种涂层，硅在整个可见光谱范围内的平均反射率可降低至小于0.1%。我们通过实验和数值模拟证明，总厚度为20 nm的渗流纳米复合材料可提供高达近红外（NIR）的抗反射性。通过改变金簇的体积填充率，ARC带宽可移动超过500 nm并拓宽至覆盖甚至近红外波长。超薄抗反射涂层的角度灵敏度在高达60°时可忽略不计。目前的ARC可应用于热光伏和测辐射热计。
