The Raman scattering in porous silicon (PSi) is modeled by means of a local bond-polarization model based on the displacement-displacement Green’s function within the linear response theory, where the Born potential is used, including central and non-central interatomic forces [1,2]. Using the supercell method, the ordered pores are produced by removing columns of Si atoms from a crystalline silicon (c-Si) structure [3]. On the other hand, the samples of PSi are obtained by anodizing p^--type (001)-oriented c-Si wafers in a hydrofluoric acid bath [4]. The morphology of PSi samples at nanometric scale is characterized by the atomic force microscopy (AFM). Both theoretical and experimental results show a notable shift of the main Raman peak towards lower energies, in comparison to the bulk c-Si signal. This shift is quantitatively analyzed within the quantum confinement framework and the morphological effects are also discussed.

[1] R.J. Elliott, J.A. Krumhansl, and P.L. Leath, Rev. Mod. Phys. 46, 465 (1974).

[2] C. Wang and R.A. Barrio, Phys. Rev. Lett. 61, 191 (1988).

[3] P. Alfaro, M. Cruz and C. Wang, Nanoscale Res. Lett. 3, 55(2008).

[4] R. Cisneros. C. Ramirez, and C.Wang, J. Phys.:Condens.Matter. 19, 395010 (2007).

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