In this work black silicon (b-Si) samples were prepared by anodic (electrochemical) etching of p-type silicon substrate in solution of hydrofluoric acid (HF). We studied influence of anodic etching conditions (etching time, electrical potential and current) on the spectral reflectance and Raman scattering spectra. Optical properties of b-Si structures were experimentally studied by UV-VIS (AvaSpec-2048) and Raman (Thermo DXR Raman) spectrometers. B-Si layer thickness of formed substrate were determined by using SCOUT software. Effective medium approximation theory (Looyenga) was used in construction of the reflectance model. Influence of the deformation of crystal lattice introduced during the substrate etching was studied by Raman scattering method. Teoretical model of the 1st order Raman scattering profile was constructed by using pseudo-Voigt function and the profile parameters were extracted. The values of biaxial tensile stress were estimated by using optimized Raman profile parameters.
If the inline PDF is not rendering correctly, you can download the PDF file here.
 H. Savin, P. Repo, G. von Gastrow, P. Ortega, E. Calle, M. Garín and R. Alcubilla, “Black silicon solar cells with interdigitated back-contacts achieve 22.1% efficiency”, Nature Nanotechnology, vol. 10, pp. 624–628, 2015.
 P. B. Clapham and M. C. Hutley, “Reduction of Lens Reflexion by the “Moth Eye” Principle”, Nature, vol. 244, pp. 281–282, 1973.
 F. Karbassian, Porous Silicon, IntechOpen Limited, London, 2018.
 B. Fodor, E. Agocs, B. Bardet, T. Defforge, F. Cayrel, D. Alquier, M. Fried, G. Gautier and P. Petrik, “Porosity and thickness characterization of porous Si and oxidized porous Si layers–an ultraviolet-visible-mid infrared ellipsometry study”, Microporous and Mesoporous Materials, vol. 227, pp. 112–120, 2016.
 N. J. Hutchinson, T. Coquil, A. Navid and L. Pilon, “Effective optical properties of highly ordered mesoporous thin films”, Thin Solid Films, vol. 518, pp. 2141–2146, 2010.
 D. Raghunathan, “Black silicon for higher efficiency in solar cells”, Applied Mechanics and Materials, vol. 787, pp. 92–96, 2015.
 J. Oh, H.-Ch. Yuan and H. M. Branz, “An 18.2%-efficient black-silicon solar cell achieved through control of carrier recombination in nanostructures”, Nature Nanotechnology, vol. 7, pp. 743–748, 2012.
 D. Losic, Electrochemically Engineered Nanoporous Materials – Methods, Properties and Applications, Springer, 2015.
 L. Canham, Handbook of Porous Silicon, Springer, 2014.
 M. J. Sailor, Porous Silicon in Practice, Wiley-VCH Verlag & Co. KGaA, Weinheim, 2012.
 V. Lehmann, Electrochemistry of Silicon, Wiley-VCH Verlag & Co. KGaA, Weinheim, 2002.
 M. Pakhotnyuk, R. S. Davidsen, M. S. Schmidt, R. Malureanu, E. Stamate, O. Hansen, “Lifetime of Nano-Structured Black Silicon for Photovoltaic Applications”, Proceedings of 32nd European Photovoltaic Solar Energy Conference and Exhibition, pp. 764–767, 2016.
 S. Franssila, Introduction to Microfabrication, Second Edition, John Wiley & Sons, Ltd., Chichester, 2010.
 A. R. Hind and L. Chomette, The determination of thin film thickness using reflectance spectroscopy – Application Note, Agilent Technologies, Inc., 2011.
 T. Hine, UV Talk Letter, Schimazu, vol. 1, 2008.
 C. F. Ramirez-Gutierrez, J. D. Castano-Yepes and M. E. Rodriguez-Garcia, “Porosity and roughness determination of porous silicon thin films by genetic algorithms”, Optik, vol. 173, pp. 271–278, 2018.
 H. G. Tompkins and E. A. Irene, Handbook of Ellipsometry, William Andrew, Inc., Norwich, 2005.
 Z. Montiel-González, S. Escobar, R. Nava, J. A. del Río and J. Tagüena-Martínez, “Role of an Oxidant Mixture as Surface Modifier of Porous Silicon Microstructures Evaluated by Spectroscopic Ellipsometry”, Scientific Reports, 2016.
 Horiba, New Amorphous Dispersion Formula – Technical Note, vol. TN12, 2006.
 Horiba, Cauchy and related Empirical Dispersion Formulae for Transparent Materials – Technical Note, vol. NT14, Horiba, 2006.
 H. Sohn, Refractive Index of Porous Silicon, Springer International Publishing Switzerland, 2014.
 A. Navid and L. Pilon, “Effect of polarization and morphology on the optical properties of absorbing nanoporous thin films”, Thin Solid Films, vol. 516, pp. 4159–4167, 2008.
 A. Garahan, L. Pilon and J. Yin, “Effective optical properties of absorbing nanoporous and nanocomposite thin films”, Journal of Applied Physics, vol. 101, pp. 014320, 2007.
 M. M. Braun and L. Pilon, “Effective optical properties of non-absorbing nanoporous thin films”, Thin Solid Films, vol. 496, pp. 505–514, 2006.
 N. J. Hutchinson, T. Coquil, E. K. Richman, S. H. Tolbert and L. Pilon, “Reflectance of surfactant-templated mesoporous silica thin films: Simulations versus experiments”, Thin Solid Films, vol. 518, pp. 2134–2140, 2010.
 H. Richter, Z. P. Wang and L. Ley, “The one phonon Raman spectrum in microcrystalline silicon”, Solid State Communications, vol. 39, pp. 625–629, 1981.