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Keywords:

  • 78.20.Bh;
  • 78.20.Ci;
  • 78.67.Bf

Abstract

In this work, we report on the study of the dielectric function of nanocrystal silicon (nc-Si) implanted in a SiO2 matrix on a silicon substrate by spectroscopic ellipsometry (SE). The formed nc-Si have an average size around 4 nm. The SE measurements are performed at an angle of incidence of 70° in air at room temperature and in the spectral range of 0.6 eV to 6.5 eV. Two models are used to extract the optical responses of nc-Si: Forouhi–Bloomer formalism and wavelength-by-wavelength inversion. The nc-Si exhibits a significant reduction in the dielectric functions in comparison with the bulk Si. We have observed a reduction of the amplitude of the E1 transition with a very weak shift of its energy position. The transition E2 is characterized by a rather broad peak with an amplitude greater than that of E1. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)