Title: Interaction between a laser beam and semiconductor nanowires: application to the Raman spectrum of Si nanowires

Authors: J. Anaya; A. Torres; A.C. Prieto; J. Jimenez; A. Rodríguez; T. Rodríguez

Addresses: GdS Optronlab, Edificio I+D, Universidad de Valladolid, Paseo de Belén 1, 47011 Valladolid, Spain ' GdS Optronlab, Edificio I+D, Universidad de Valladolid, Paseo de Belén 1, 47011 Valladolid, Spain ' GdS Optronlab, Edificio I+D, Universidad de Valladolid, Paseo de Belén 1, 47011 Valladolid, Spain ' GdS Optronlab, Edificio I+D, Universidad de Valladolid, Paseo de Belén 1, 47011 Valladolid, Spain ' Dpto. Tecnología Electrónica, E.T.S.I. de Telecomunicación, Universidad Politécnica de Madrid, 28040 Madrid, Spain ' Dpto. Tecnología Electrónica, E.T.S.I. de Telecomunicación, Universidad Politécnica de Madrid, 28040 Madrid, Spain

Abstract: One presents in this work the study of the interaction between a focused laser beam and Si nanowires (NWs). The NWs heating induced by the laser beam is studied by solving the heat transfer equation by finite element methods (FEM). This analysis permits to establish the temperature distribution inside the NW when it is excited by the laser beam. The overheating is dependent on the dimensions of the NW, both the diameter and the length. When performing optical characterisation of NWs using focused laser beams, one has to consider the temperature increase introduced by the laser beam. An important issue concerns the fact that the NW's diameter has subwavelength dimensions, and is also smaller than the focused laser beam. The analysis of the thermal behaviour of the NWs under the excitation with the laser beam permits the interpretation of the Raman spectrum of Si NWs. It is demonstrated that the temperature increase induced by the laser beam plays a major role in shaping the Raman spectrum of Si NWs.

Keywords: silicon nanowires; Raman spectroscopy; thermal conductivity; laser heating; phonons; laser beams; semiconductor nanowires; nanotechnology; temperature distribution.

DOI: 10.1504/IJNP.2013.054985

International Journal of Nanoparticles, 2013 Vol.6 No.2/3, pp.103 - 112

Published online: 21 Jun 2013 *

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