Kjeldstad Torunn, Thøgersen Annett, Stange Marit, Jensen Ingvild Thue, Monakhov Eduard, Galeckas Augustinas
Department of Physics/Centre for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo, Norway.
SINTEF Industry, P.O. Box 124 Blindern, 0314 Oslo, Norway.
Nanomaterials (Basel). 2019 Aug 1;9(8):1106. doi: 10.3390/nano9081106.
We present a study of the surface effects and optical properties of the self-assembled nanostructures comprised of vertically aligned 5 nm-diameter Al nanowires embedded in an amorphous Si matrix (a-Si:Al). The controlled (partial) removal of Al nanowires in a selective etching process yielded nanoporous a-Si media with a variable effective surface area. Different spectroscopy techniques, such as X-ray photoelectron spectroscopy (XPS), UV-Vis spectrophotometry and photoluminescence (PL), have been combined to investigate the impact of such nanostructuring on optical absorption and emission properties. We also examine long-term exposure to air ambient and show that increasing level of surface oxidation determines the oxide defect-related nature of the dominant PL emission from the nanoporous structures. The role of bulk, nanosize and surface effects in optical properties has been separated and quantified, providing a better understanding of the potential of such nanoporous a-Si:Al structures for future device developments.
我们展示了一项关于自组装纳米结构的表面效应和光学性质的研究，该纳米结构由嵌入非晶硅基质（a-Si:Al）中的垂直排列的直径为5纳米的铝纳米线组成。在选择性蚀刻过程中对铝纳米线进行可控（部分）去除，得到了具有可变有效表面积的纳米多孔a-Si介质。不同的光谱技术，如X射线光电子能谱（XPS）、紫外-可见分光光度法和光致发光（PL），已被结合起来研究这种纳米结构对光吸收和发射性质的影响。我们还研究了长期暴露在空气环境中的情况，并表明表面氧化程度的增加决定了纳米多孔结构中主导PL发射的与氧化物缺陷相关的性质。已将体效应、纳米尺寸效应和表面效应在光学性质中的作用分离并量化，从而更好地理解这种纳米多孔a-Si:Al结构在未来器件开发中的潜力。
