Terahertz Spectroscopy to Unveil Intraband Scattering in Photoexcited Graphene

© 2019 IEEE. Intraband scattering dynamics of optically excited graphene has been explored by using time resolved terahertz spectroscopy. The results for different forms of graphene in terms of layers, Fermi energy position, hydrogen functionalization have been discussed and explained by using Boltzmann transport theory. It is shown how the short-range and Coulomb scattering play important roles in determining photo-induced terahertz conductivity. While photoexcited single layer graphene showed completely negative photoinduced terahertz conductivity (the real part), photoexcited bilayer graphene showed transition from negative to positive in the spectral range 0.5-2.5 THz