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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

T-TYPE RAMAN METHOD FOR NON-CONTACT CHARACTERIZATION OF THERMAL TRANSPORT PROPERTIES OF INDIVIDUAL NANOWIRES

Get access (open in a dialog) DOI: 10.1615/IHTC16.nmt.023847
pages 7273-7281

Аннотация

Nanowires have promising applications in micro/nano electronics, photoelectric conversion and thermoelectric conversion due to their distinctive merits. Thermal transport properties of nanowires are the fundamental parameters for the thermal design of micro/nano devices. Problems arise, thermal transport properties of nanowires are significantly different from their corresponding bulk values due to the size effects. Moreover, the thermometry methods applied in macro scale no longer meet the requirement of nanowire measurements. In this paper, we present a non-contact T-type Raman method for characterizing thermal transport properties of various nanowires. The thermal transport properties of the nano-sensor (silicon nanowire) using our new developed laser flash-Raman spectroscopy method, which directly extracts the thermal diffusivity (α) by comparing the continuous laser and square pulse laser heating induced temperature rise. An individual single crystal silicon nanowire with 490 nm diameter prepared by metal-assisted chemical etching was characterized in the temperature range from 223 K to 473 K, the results indicated a decreases from 6.4×10-5 m2/s to 2.0×10-5 m2/s, λ decreases from 76.4 W/(m·K) to 38.7 W/(m·K) which was derived by λ=αρCp. Both α and λ are significantly lower than that of the corresponding bulk values, indicating surface scattering greatly reduced the phonon mean free path (MFP). Then, the test nanowire's thermal properties can be extracted by comparing the same laser spot heating the sensor induced local temperature rises before and after the test nanowire attaching to the sensor.