Ultrafast relaxation of highly excited hot electrons in Si: Roles of the L-X intervalley scattering

Ichibayashi T, Tanaka S, Kanasaki J, Tanimura K, Fauster T (2011)


Publication Status: Published

Publication Type: Journal article

Publication year: 2011

Journal

Publisher: American Physical Society

Book Volume: 84

Article Number: 235210

DOI: 10.1103/PhysRevB.84.235210

Abstract

Two-photon photoemission (2PPE) spectroscopy is used to reveal dynamic relaxation of highly excited electrons generated by 3 eV photons in Si. Monochromatic 2PPE at probe-photon energies ranging from 3.2 to 3.5 eV reveals a coherent 2PPE peak from the valence band maximum, and a transiently populated photoemission peak near L(1) in the conduction band. Time-resolved 2PPE measurements show that electrons injected into the L valley undergo L-to-X intervalley scattering with a time constant of 180 fs at 293 K. A deformation potential constant of 1.2 eV angstrom(-1) is obtained for the scattering. The highly excited electrons are relaxed down around the conduction band minimum to form a quasi-equilibrated hot electron distribution; the highest density is accumulated at 660 fs after excitation. The hot electron distribution is equilibrated with the lattice within 2 ps after excitation. These results are compared to relaxation processes of electrons injected directly into the X valley by photons with energies below 2.2 eV.

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APA:

Ichibayashi, T., Tanaka, S., Kanasaki, J., Tanimura, K., & Fauster, T. (2011). Ultrafast relaxation of highly excited hot electrons in Si: Roles of the L-X intervalley scattering. Physical Review B, 84. https://dx.doi.org/10.1103/PhysRevB.84.235210

MLA:

Ichibayashi, Taku, et al. "Ultrafast relaxation of highly excited hot electrons in Si: Roles of the L-X intervalley scattering." Physical Review B 84 (2011).

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