Simultaneous Measurement of Thermal Conductivity and Specific Heat in a Single TDTR Experiment
Time-domain thermoreflectance (TDTR) technique is a powerful thermal property measurement method, especially for nano-structures and material interfaces. Thermal properties can be obtained by fitting TDTR experimental data with a proper thermal transport model. In a single TDTR experiment, thermal properties with different sensitivity trends can be extracted simultaneously. However, thermal conductivity and volumetric heat capacity usually have similar trends in sensitivity for most materials; it is difficult to measure them simultaneously. In this work, we present a two-step data fitting method to measure the thermal conductivity and volumetric heat capacity simultaneously from a set of TDTR experimental data at single modulation frequency. This method takes full advantage of the information carried by both amplitude and phase signals; it is a more convenient and effective solution compared with the frequency-domain thermoreflectance method. The relative error is lower than 5 % for most cases. A silicon wafer sample was measured by TDTR method to verify the two-step fitting method.
KeywordsSpecific heat Thermal conductivity Thermal property Time-domain thermoreflectance Two-step fitting method
F.S. thanks the financial support from National Natural Science Foundation of China (Grant Nos. 51606193 & 51373184) and Ministry of Science and Technology of the People’s Republic of China (Grant No. 2013YQ120355). H.Z. thanks the financial support from CAS Pioneer Hundred Talents Program.
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