Dielectric properties of extended defects in silicon studied by high-resolution transmission EELS

We have found that the nanoscale defective structure of the {113} extended defect in silicon which consists of no dangling bond gives rise to the change of dielectric properties by means of high-resolution transmission electron energy-loss spectroscopy (HR-TEELS). The dielectric functions of nanoscale regimes were determined from the loss-functions by the Kramers-Kronig analysis. The peak in the imaginary part of the dielectric function epsilon(2) measured from the defective region shifts at 2.0-2.5 eV. We attribute the result to the nonvertical interband transitions between the localized defect states at the band edges and/or the effect of the periodicity breakdown.