Anisotropic Thermal Conductivity in Single Crystal beta-Gallium Oxide

Abstract

The thermal conductivities of beta-Ga2O3 single crystals along four different crystal directions were measured in the temperature range of 80-495K using the time domain thermoreflectance (TDTR) method. A large anisotropy was found. At room temperature, the [010] direction has the highest thermal conductivity of 27.0+/-2.0 W/mK, while that along the [100] direction has the lowest value of 10.9+/-1.0 W/mK. At high temperatures, the thermal conductivity follows a ~1/T relationship characteristic of Umklapp phonon scattering, indicating phonon-dominated heat transport in the \b{eta}-Ga2O3 crystal. The measured experimental thermal conductivity is supported by first-principles calculations which suggest that the anisotropy in thermal conductivity is due to the differences of the speed of sound along different crystal directions.

9 pages, 3 figures

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• Anisotropic Thermal Conductivity in Single Crystal beta-Gallium Oxide
• Gallium Arsenide Thermal Conductivity and Optical Phonon Relaxation Times from First-Principles Calculations
• Temperature-dependent thermal conductivity in Mg-doped and undoped $\beta$-$\mathrm{G}{\mathrm{a}}_2{\mathrm{O}}_3$ bulk-crystals

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• Beam damage of single semiconductor nanowires during X-ray nano beam diffraction experiments
• Wafer-scale Heterogeneous Integration of Monocrystalline \b{eta}-Ga2O3 Thin Films on SiC for Thermal Management by Ion-Cutting Technique