1. Nanoscale heat transport from Ge hut, dome, and relaxed clusters on Si(001) measured by ultrafast electron diffraction.
- Author
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Frigge, T., Hafke, B., Tinnemann, V., Krenzer, B., and Horn-von Hoegen, M.
- Subjects
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OPTICAL properties of silicon , *NANOSTRUCTURED materials synthesis , *SILICON spectra , *THERMAL properties of nanostructured materials , *ELECTRON diffraction , *GERMANIUM crystals , *HEAT transfer , *SEMICONDUCTOR growth - Abstract
The thermal transport properties of crystalline nanostructures on Si were studied by ultra-fast surface sensitive time-resolved electron diffraction. Self-organized growth of epitaxial Ge hut, dome, and relaxed clusters was achieved by in-situ deposition of 8 monolayers of Ge on Si(001) at 550 °C under UHV conditions. The thermal response of the three different cluster types subsequent to impulsive heating by fs laser pulses was determined through the Debye-Waller effect. Time resolved spot profile analysis and life-time mapping was employed to distinguish between the thermal response of the different cluster types. While dome clusters are cooling with a time constant of τ = 150 ps, which agrees well with numerical simulations, the smaller hut clusters with a height of 2.3 nm exhibit a cooling time constant of τ = 50 ps, which is a factor of 1.4 slower than expected. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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