Investigation of the optical and conductive properties of antimony-doped titanium dioxide using terahertz time-domain spectroscopy

The refractive index, absorption coefficient, dielectric constant and conductivity of titanium dioxide at different doping concentrations of antimony (Sb) have been investigated using the non-contact and damage-free technique of terahertz time-domain spectroscopy. Simple effective medium theory has been applied to composite samples to extract the dielectric and conductive response in the range of 0.2-1.2 THz. The frequency-dependent values of these parameters are observed to increase with doping concentration and also with calcination temperature. Drude-Smith model fitting with the measured conductivity curves reveals that back-scattering is the major conductivity mechanism.