Krenzer, Boris; Hanisch-Blicharski, Anja; Schneider, P.; Payer, Thomas; Möllenbeck, Simone; Osmani, Orkahn; Kammler, Martin; Meyer, Ralf; Horn-von Hoegen, Michael:
Phonon confinement effects in ultrathin epitaxial bismuth films on silicon studied by time-resolved electron diffraction
2009
In: Physical Review. B, Jg. 80 (2009), Heft 2, S. 24307
Artikel/Aufsatz in Zeitschrift / Fach: Physik
Fakultät für Physik » Experimentalphysik
Zentrale wissenschaftliche Einrichtungen » Center for Nanointegration Duisburg-Essen (CENIDE)
Titel:
Phonon confinement effects in ultrathin epitaxial bismuth films on silicon studied by time-resolved electron diffraction
Autor(in):
Krenzer, Boris; Hanisch-Blicharski, Anja im Online-Personal- und -Vorlesungsverzeichnis LSF anzeigen; Schneider, P.; Payer, Thomas im Online-Personal- und -Vorlesungsverzeichnis LSF anzeigen; Möllenbeck, Simone; Osmani, Orkahn im Online-Personal- und -Vorlesungsverzeichnis LSF anzeigen; Kammler, Martin im Online-Personal- und -Vorlesungsverzeichnis LSF anzeigen; Meyer, Ralf im Online-Personal- und -Vorlesungsverzeichnis LSF anzeigen; Horn-von Hoegen, Michael im Online-Personal- und -Vorlesungsverzeichnis LSF anzeigen
Erscheinungsjahr:
2009
Erschienen in:
Physical Review. B, Jg. 80 (2009), Heft 2, S. 24307
ISSN:
ISSN:
ISSN:
DOI:

Abstract:

The transient temperature evolution of ultrathin bismuth films, epitaxially grown on a silicon single crystal, upon femtosecond laser excitation is studied by time-resolved electron diffraction. The exponential decay of the film temperature is explained by phonon reflection at the interface, which results in a strongly reduced thermal conduction in the cross plane of the layered system. The thermal boundary conductance is found to be as low as 1273 W/(K cm2). Model calculations, including phonon confinement effects, explain the linear relationship between the observed film-temperature decay constant and the film thickness. Even for 2.5 nm thin films the phonon transmission probability across the interface is given by bulk properties. Our simulations show that phonon confinement effects are negligible for bismuth-film thicknesses larger than 1 nm.