Details
| Original language | English |
|---|---|
| Article number | 172202 |
| Journal | Applied physics letters |
| Volume | 127 |
| Issue number | 17 |
| Publication status | Published - 27 Oct 2025 |
Abstract
Heat transfer is a critical aspect of modern electronics, and a deeper understanding of the underlying physics is essential for building faster, smaller, and more powerful devices with improved performance and efficiency. In such nanoscale structures, the heat transfer between two materials is limited by the finite thermal boundary conductance across their interface. Using ultrafast electron diffraction under grazing incidence we investigated the heat transfer from ultrathin epitaxial Pb films to an Si(111) substrate under strong nonequilibrium conditions. Upon applying an intense femtosecond laser pulse, the 5-7 ML thin Pb film undergoes rapid heating by 10-120 K while the Si substrate remains cold at ≈ 10 K . At such large temperature discontinuities, a significantly faster cooling is observed for more strongly excited Pb films. The decrease in the corresponding cooling time constant is explained by variations in thermal boundary conductance, interpreted within the framework of the diffuse mismatch model. The thermal boundary conductance is reduced by more than a factor of three in comparison with Pb films grown on H-terminated substrates, underscoring the importance of substrate, heterofilm, and interface morphologies.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physics and Astronomy (miscellaneous)
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In: Applied physics letters, Vol. 127, No. 17, 172202, 27.10.2025.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Thermal boundary conductance under large temperature discontinuities of ultrathin Pb(111) films on Si(111)
AU - Brand, Christian
AU - Witte, Tobias
AU - Tajik, Mohammad
AU - Fortmann, Jonas D.
AU - Finke, Birk
AU - Pfnür, Herbert
AU - Tegenkamp, Christoph
AU - Horn-Von Hoegen, Michael
N1 - Publisher Copyright: © 2025 Author(s).
PY - 2025/10/27
Y1 - 2025/10/27
N2 - Heat transfer is a critical aspect of modern electronics, and a deeper understanding of the underlying physics is essential for building faster, smaller, and more powerful devices with improved performance and efficiency. In such nanoscale structures, the heat transfer between two materials is limited by the finite thermal boundary conductance across their interface. Using ultrafast electron diffraction under grazing incidence we investigated the heat transfer from ultrathin epitaxial Pb films to an Si(111) substrate under strong nonequilibrium conditions. Upon applying an intense femtosecond laser pulse, the 5-7 ML thin Pb film undergoes rapid heating by 10-120 K while the Si substrate remains cold at ≈ 10 K . At such large temperature discontinuities, a significantly faster cooling is observed for more strongly excited Pb films. The decrease in the corresponding cooling time constant is explained by variations in thermal boundary conductance, interpreted within the framework of the diffuse mismatch model. The thermal boundary conductance is reduced by more than a factor of three in comparison with Pb films grown on H-terminated substrates, underscoring the importance of substrate, heterofilm, and interface morphologies.
AB - Heat transfer is a critical aspect of modern electronics, and a deeper understanding of the underlying physics is essential for building faster, smaller, and more powerful devices with improved performance and efficiency. In such nanoscale structures, the heat transfer between two materials is limited by the finite thermal boundary conductance across their interface. Using ultrafast electron diffraction under grazing incidence we investigated the heat transfer from ultrathin epitaxial Pb films to an Si(111) substrate under strong nonequilibrium conditions. Upon applying an intense femtosecond laser pulse, the 5-7 ML thin Pb film undergoes rapid heating by 10-120 K while the Si substrate remains cold at ≈ 10 K . At such large temperature discontinuities, a significantly faster cooling is observed for more strongly excited Pb films. The decrease in the corresponding cooling time constant is explained by variations in thermal boundary conductance, interpreted within the framework of the diffuse mismatch model. The thermal boundary conductance is reduced by more than a factor of three in comparison with Pb films grown on H-terminated substrates, underscoring the importance of substrate, heterofilm, and interface morphologies.
UR - http://www.scopus.com/inward/record.url?scp=105019953401&partnerID=8YFLogxK
U2 - 10.1063/5.0291617
DO - 10.1063/5.0291617
M3 - Article
AN - SCOPUS:105019953401
VL - 127
JO - Applied physics letters
JF - Applied physics letters
SN - 0003-6951
IS - 17
M1 - 172202
ER -