Terahertz time-domain spectroscopy of anisotropic complex conductivity tensors in silicon nanowire films

Abstract

The effective complex conductivity tensor of a highly anisotropic, vertically aligned silicon nanowire film was measured by terahertz time-domain spectroscopy. The silicon nanowires were fabricated on a p-type silicon substrate by metal-assisted chemical etching, which resulted in a film with uniaxially anisotropic optical properties. The measured terahertz transverse and longitudinal conductivity values were in excellent agreement with the results of calculations based on the Drude-Smith and Lorentz models, respectively.