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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 20, 2015
- Source ID
- 10.1063/1.4935366
Entities
People
- Johanna Wolfson
- Keith A. Nelson
- Maria Kandyla
- Samuel W Teitelbaum
- Taeho Shin
Organizations
- Massachusetts Institute of Technology
- National Science Foundation
- Office of Naval Research
- Samsung Group