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Coherent acoustic phonon oscillations and transient critical point parameters of Ge from femtosecond pump‐probe ellipsometry

Emminger, Carola ; Espinoza, Shirly ; Richter, Steffen LU ; Rebarz, Mateusz ; Herrfurth, Oliver ; Zahradník, Martin ; Schmidt-grund, Rüdiger ; Andreasson, Jakob and Zollner, Stefan (2022) In Physica Status Solidi - Rapid Research Letters 16(7).
Abstract
The complex pseudodielectric function of Ge and Si from femtosecond pump-probe spectroscopic ellipsometry with 267, 400, and 800 nm pump-pulse wavelengths is analyzed by fitting analytical lineshapes to the second derivatives of the pseudodielectric function with respect to energy. This yields the critical point parameters (threshold energy, lifetime broadening, amplitude, and excitonic phase angle) of E1 and E1+Δ1 in Ge and E1 in Si as functions of delay time. Coherent longitudinal acoustic phonon oscillations with a period of about 11 ps are observed in the transient critical point parameters of Ge. From the amplitude of these oscillations, the laser-induced strain is found to be on the order of 0.1% for Ge measured with the 800 nm pump... (More)
The complex pseudodielectric function of Ge and Si from femtosecond pump-probe spectroscopic ellipsometry with 267, 400, and 800 nm pump-pulse wavelengths is analyzed by fitting analytical lineshapes to the second derivatives of the pseudodielectric function with respect to energy. This yields the critical point parameters (threshold energy, lifetime broadening, amplitude, and excitonic phase angle) of E1 and E1+Δ1 in Ge and E1 in Si as functions of delay time. Coherent longitudinal acoustic phonon oscillations with a period of about 11 ps are observed in the transient critical point parameters of Ge. From the amplitude of these oscillations, the laser-induced strain is found to be on the order of 0.1% for Ge measured with the 800 nm pump pulse, which is in reasonable agreement with the strain calculated from theory. (Less)
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physica Status Solidi - Rapid Research Letters
volume
16
issue
7
article number
2200058
publisher
John Wiley & Sons Inc.
external identifiers
  • scopus:85131056773
ISSN
1862-6254
DOI
10.1002/pssr.202200058
language
English
LU publication?
yes
id
95a011cf-d47f-4633-aa1c-bff96b94ba30
alternative location
https://onlinelibrary.wiley.com/doi/10.1002/pssr.202200058
date added to LUP
2022-05-18 18:39:53
date last changed
2023-12-18 14:50:06
@article{95a011cf-d47f-4633-aa1c-bff96b94ba30,
  abstract     = {{The complex pseudodielectric function of Ge and Si from femtosecond pump-probe spectroscopic ellipsometry with 267, 400, and 800 nm pump-pulse wavelengths is analyzed by fitting analytical lineshapes to the second derivatives of the pseudodielectric function with respect to energy. This yields the critical point parameters (threshold energy, lifetime broadening, amplitude, and excitonic phase angle) of E1 and E1+Δ1 in Ge and E1 in Si as functions of delay time. Coherent longitudinal acoustic phonon oscillations with a period of about 11 ps are observed in the transient critical point parameters of Ge. From the amplitude of these oscillations, the laser-induced strain is found to be on the order of 0.1% for Ge measured with the 800 nm pump pulse, which is in reasonable agreement with the strain calculated from theory.}},
  author       = {{Emminger, Carola and Espinoza, Shirly and Richter, Steffen and Rebarz, Mateusz and Herrfurth, Oliver and Zahradník, Martin and Schmidt-grund, Rüdiger and Andreasson, Jakob and Zollner, Stefan}},
  issn         = {{1862-6254}},
  language     = {{eng}},
  month        = {{05}},
  number       = {{7}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{Physica Status Solidi - Rapid Research Letters}},
  title        = {{Coherent acoustic phonon oscillations and transient critical point parameters of Ge from femtosecond pump‐probe ellipsometry}},
  url          = {{http://dx.doi.org/10.1002/pssr.202200058}},
  doi          = {{10.1002/pssr.202200058}},
  volume       = {{16}},
  year         = {{2022}},
}