Infrared spectroscopy of silicon for applications in astronomy

Abstract

This work focuses on the characterization of various bulk silicon (Si) samples using Fourier Transform InfraRed (FTIR) and grating spectrometers in order to get them suitable for applications in astronomy. Different samples at different impurity concentrations were characterized by measuring their transmittance in the infrared region. Various lines due to residual impurity absorption were identified and temperature dependence of impurity absorption is presented. Concentrations of doped samples (ρ ≈ 0.2 -25000 Ωcm) were determined from impurity absorption at low temperatures and from Drude free carrier absorption at 300K.