Limits to Fourier theory in high thermal conductivity single crystals

R. B. Wilson, David G. Cahill

Research output: Contribution to journalArticle


We report the results of time-domain thermoreflectance (TDTR) experiments that examine the ability of Fourier theory to predict the thermal response in single crystals when heater dimensions are small. We performed TDTR measurements on Al-coated diamond, 6H-SiC, GaP, Ge, MgO, GaAs, and GaSb single crystals with a wide range of laser spot size radii, 0.7 μm < w 0 < 12 μm. When the laser spot-size is large, w 0 ≈ 12 μm, TDTR data for all crystals are in agreement with predictions of Fourier theory with bulk thermal conductivity values. When the laser spot-size is small, w 0 < 2 μm, there are significant differences between the predictions of Fourier theory and TDTR data for all crystals except MgO.

Original languageEnglish (US)
Article number203112
JournalApplied Physics Letters
Issue number20
StatePublished - Nov 16 2015


ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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