Terahertz Response from a Silicon Surface with Deposited Nanosized Gold Particles

Abstract

Terahertz emission spectra of the surface of silicon crystals with different types of conductivity were experimentally recorded upon excitation by femtosecond laser pulses at various temperatures. The observed features in the terahertz spectra of the silicon surface correspond to the energy structure of the impurity centers determining the type of conductivity of the sample. Comparison was made with the results obtained in the case of deposition of gold nanoparticles on a semiconductor surface. The spectral features of the surface with deposited nanoparticles are discussed using the terahertz re-emission mechanism in two-phonon absorption.