Saitta, M. A. and Buda, F. and Fiumara, G. and Giaquinta, P. V. (1994) Proprietà ottiche ed elettroniche di quantum wires di silicio: effetti orientazionali. Accademia Peloritana dei Pericolanti, Classe di Scienze FF. MM. NN., LXXII (s). pp. 681-688.
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The aim of this work is to analyze the influence of the orientation of the wire on the optical response of the material. We compare the present results with those previously obtained within the same theoretical framework for (001)-oriented wires [F. Buda, J. Kohanoff and M. Parrinello, Phys. Rev. Lett. 69, 1272 (1992)].
In analogy with the (001)-oriented wire and at variance with crystalline bulk silicon, we find that the (111)-oriented wire exhihits a direct hand gap at =0 whose value is largely enhanced with respect to that found in bulk silicon because of quantum confinement effects.
The imaginary part of the dielectric function, for the external field polarized in the direction of the axis of the wire, shows features that, while being qualitatively similar to those observed for the (001) wire, are not present in the bulk.
The main conclusion that emerges from the present study is that, if wires a few nanometers large are present in the porous material, they will be optically active independently of their specific orientation. This prediction appears to be consistent with polarization Raman measurernents, which suggest that the porous silicon structure consists of a series of randomly oriented wires.
|Subjects:||M.U.S. - Miscellanea > Atti Accademia Peloritana > Classe di Scienze Fisiche, Matematiche e Naturali > 1994 > Supplemento 1 parte 2|
M.U.S. - Miscellanea > Atti Accademia Peloritana > Classe di Scienze Medico-Biologiche > 1994 > Supplemento 1 parte 2
M.U.S. - Miscellanea > Atti Accademia Peloritana > Classe di Scienze Giuridiche, Economiche e Politiche > 1994 > Supplemento 1 parte 2
M.U.S. - Miscellanea > Atti Accademia Peloritana > Classe di Lettere, Filosofia e belle Arti > 1994 > Supplemento 1 parte 2
|Depositing User:||Mr Nunzio Femminò|
|Date Deposited:||18 Apr 2014 12:50|
|Last Modified:||18 Apr 2014 12:50|
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