Transient dielectric functions of Ge, Si, and InP from femtosecond pump-probe ellipsometry

0521463 - FZÚ 2021 RIV US eng J - Journal Article
Espinoza Herrera, Shirly J. - Richter, Steffen - Rebarz, Mateusz - Herrfurth, O. - Schmidt-Grund, R. - Andreasson, Jakob - Zollner, S.
Transient dielectric functions of Ge, Si, and InP from femtosecond pump-probe ellipsometry.
Applied Physics Letters. Roč. 115, č. 5 (2019), s. 1-4, č. článku 052105. ISSN 0003-6951. E-ISSN 1077-3118
R&D Projects: GA MŠMT LQ1606
Research Infrastructure: ELI Beamlines II - 90094
Institutional support: RVO:68378271
Keywords : deformation potentials * temperature-dependence * critical-points * GaAs
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 3.597, year: 2019
Method of publishing: Open access

Transient dielectric functions with a 120 fs time resolution of Ge, Si, and InP were acquired from 1.7 to 3.5eV with a femtosecond pump-probe rotating-compensator ellipsometer. The intensity of the pump laser (with 1.55, 3.10, or 4.65eV photon energy) was adjusted to create an initial near-surface carrier density of 10(20)cm(-3). In Ge, there is a significant (similar to 15%) decrease in the E-1 and E-1+Delta(1) critical point absorption and a Kramers-Kronig consistent change in the refractive index because photoexcited electrons at L block these transitions and reduce their amplitudes. Only a small redshift of the E-1 critical point is observed, which we attribute to lattice heating and exchange-correlation effects. Minimal changes were found for Si and InP, where electrons near Delta and Gamma do not participate in interband transitions between 1.7 and 3.5eV.
Permanent Link: http://hdl.handle.net/11104/0306082