title: Extended two-temperature model for ultrafast thermal response of band gap materials upon impulsive optical excitation.
abstract: Thermal modeling and numerical simulations have been performed to describe the ultrafast thermal response of band gap materials upon optical excitation. A model was established by extending the conventional two-temperature model that is adequate for metals, but not for semiconductors. It considers the time- and space-dependent density of electrons photoexcited to the conduction band and accordingly allows a more accurate description of the transient thermal equilibration between the hot electrons and lattice. Ultrafast thermal behaviors of bismuth, as a model system, were demonstrated using the extended two-temperature model with a view to elucidating the thermal effects of excitation laser pulse fluence, electron diffusivity, electron-hole recombination kinetics, and electron-phonon interactions, focusing on high-density excitation.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA.
authors.forename: Taeho
authors.initials: T
authors.lastname: Shin
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA.
authors.forename: Samuel W
authors.initials: SW
authors.lastname: Teitelbaum
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA.
authors.forename: Johanna
authors.initials: J
authors.lastname: Wolfson
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Kandyla
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Nelson