DBPapers
DOI: 10.5593/sgem2017/61/S24.019

FEATURES OF TOTAL OPTICAL REFLECTION IN SILICON NANOSTRUCTURES OBTAINED BY METAL ASSISTED CHEMICAL ETCHING

G.K. Mussabek, R.B. Assilbayeva, D. Yermukhamed, G.S. Yar-Mukhamedova, V.Y. Timoshenko
Tuesday 12 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-12-6 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 61, 141-148 pp, DOI: 10.5593/sgem2017/61/S24.019

ABSTRACT

Total (specular+diffusive) reflection of nanostructured Si layers prepared by metal assisted chemical etching (MACE) of crystalline silicon (c-Si) wafers is investigated. The thickness of nanostructured Si layers is varied from 0.3 to 100 μm by increasing the MACE time. The time dependence of silicon nanostructured layers thickness on the etching time was found to be logarithmic. Spectra of the total reflection were measured in optical range from 0.2 to 2 μm. Depending on the thickness of sample, it was observed a low level of the total reflection near 1% in the ultraviolet (UV)-visible spectral ranges and a strong increase up to 80% in the infrared (IR) optical range above 1 μm. The low reflection in UV-visible region is explained by partial localization of light in Si nanostructures accompanied with the strong light absorption. The enhanced IR reflection is probably related to the strong scattering of light by silicon nanocrystals in the transparency region. The maximal total reflection in the IR range was found for the layer thickness of about 30 μm. An effect of doping of Si nanostructures by donor and acceptor impurities on the total reflection in the IR region was observed. The obtained results can be useful to prepare new materials with desired properties for photonic applications.

Keywords: silicon, nanostructures, total reflection, optics.