Hot Electron Thermoreflectance Coefficient of Gold during Electron-Phonon Nonequilibrium

Elizabeth L. Radue, John A. Tomko, Ashutosh Giri, Jeffrey L. Braun, Xin Zhou, Oleg V. Prezhdo, Evan L. Runnerstrom, Jon Paul Maria, Patrick E. Hopkins

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The temperature-dependent reflectivity of metals is quantified by the thermoreflectance coefficient, which is a material-dependent parameter that depends on the metallic band structure, electron scattering dynamics, and photon wavelength. After short-pulse laser heating, the electronic subsystem in a metal can be driven to temperatures much higher than that of the lattice, which gives rise to unique nonequilibrium electron and phonon scattering dynamics, leading to a "hot electron" thermoreflectance that is different from the traditionally measured equilibrium coefficient. In this work, we analytically quantify and experimentally measure this hot electron thermoreflectance coefficient through ultrafast pump-probe measurements of thin gold films on silica glass and sapphire substrates. We demonstrate the ability to not only quantify the thermoreflectance during electron-phonon nonequilibrium but also validate this coefficient's predicted dependence on the absolute temperature of the electronic subsystem. The approach outlined in this work provides a metrology to further understand and quantify excited-state scattering effects on the dielectric function of metals.

Original languageEnglish (US)
Pages (from-to)4880-4887
Number of pages8
JournalACS Photonics
Volume5
Issue number12
DOIs
StatePublished - Dec 19 2018

Fingerprint

Phonons
Hot electrons
hot electrons
Gold
Electron scattering
Metals
Electrons
gold
coefficients
Laser heating
electron scattering
Phonon scattering
electrons
Aluminum Oxide
Temperature
metals
Fused silica
Excited states
pulse heating
Sapphire

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Biotechnology
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering

Cite this

Radue, E. L., Tomko, J. A., Giri, A., Braun, J. L., Zhou, X., Prezhdo, O. V., ... Hopkins, P. E. (2018). Hot Electron Thermoreflectance Coefficient of Gold during Electron-Phonon Nonequilibrium. ACS Photonics, 5(12), 4880-4887. https://doi.org/10.1021/acsphotonics.8b01045
Radue, Elizabeth L. ; Tomko, John A. ; Giri, Ashutosh ; Braun, Jeffrey L. ; Zhou, Xin ; Prezhdo, Oleg V. ; Runnerstrom, Evan L. ; Maria, Jon Paul ; Hopkins, Patrick E. / Hot Electron Thermoreflectance Coefficient of Gold during Electron-Phonon Nonequilibrium. In: ACS Photonics. 2018 ; Vol. 5, No. 12. pp. 4880-4887.
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Radue, EL, Tomko, JA, Giri, A, Braun, JL, Zhou, X, Prezhdo, OV, Runnerstrom, EL, Maria, JP & Hopkins, PE 2018, 'Hot Electron Thermoreflectance Coefficient of Gold during Electron-Phonon Nonequilibrium', ACS Photonics, vol. 5, no. 12, pp. 4880-4887. https://doi.org/10.1021/acsphotonics.8b01045

Hot Electron Thermoreflectance Coefficient of Gold during Electron-Phonon Nonequilibrium. / Radue, Elizabeth L.; Tomko, John A.; Giri, Ashutosh; Braun, Jeffrey L.; Zhou, Xin; Prezhdo, Oleg V.; Runnerstrom, Evan L.; Maria, Jon Paul; Hopkins, Patrick E.

In: ACS Photonics, Vol. 5, No. 12, 19.12.2018, p. 4880-4887.

Research output: Contribution to journalArticle

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AU - Tomko, John A.

AU - Giri, Ashutosh

AU - Braun, Jeffrey L.

AU - Zhou, Xin

AU - Prezhdo, Oleg V.

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AU - Maria, Jon Paul

AU - Hopkins, Patrick E.

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Radue EL, Tomko JA, Giri A, Braun JL, Zhou X, Prezhdo OV et al. Hot Electron Thermoreflectance Coefficient of Gold during Electron-Phonon Nonequilibrium. ACS Photonics. 2018 Dec 19;5(12):4880-4887. https://doi.org/10.1021/acsphotonics.8b01045