Ballistic thermal transport in silicon nanowires.
We have experimentally investigated the impact of dimensions and temperature on the thermal conductivity of silicon nanowires fabricated using a top-down approach. Both the width and temperature dependences of thermal conductivity agree with those in the existing literature. The length dependence of thermal conductivity exhibits a transition from semi-ballistic thermal phonon transport at 4 K to fully diffusive transport at room temperature. We additionally calculated the phonon dispersion in these structures in the framework of the theory of elasticity and showed that the thermal conductance increases with width. This agrees with our experimental observations and supports the pertinence of using the modified phonon dispersion at low temperatures.
Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505, Japan.|Laboratory for Integrated Micro Mechatronic Systems/National Center for Scientific Research-Institute of Industrial Science (LIMMS/CNRS-IIS), The University of Tokyo, Tokyo 153-8505, Japan.
Jeremie
J
Maire
Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505, Japan.
Roman
R
Anufriev
Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505, Japan.|Institute for Nano Quantum Information Electronics, The University of Tokyo, Tokyo 153-8505, Japan.|PRESTO, Japan Science and Technology Agency, Saitama 332-0012, Japan.
Masahiro
M
Nomura