DOI: 10.1615/ICHMT.2015.IntSympAdvComputHeatTransf
ISBN Print: 978-1-56700-429-8
ISSN: 2578-5486
EXPLORING CONTROLLABILITY OF THERMAL CONDUCTIVITY FOR HIGH PERFORMANCE BULK SILICON THERMOELECTRIC
摘要
Responding to the need for thermoelectric materials with high efficiency in both conversion and cost, we have been developing a nanostructured bulk silicon thermoelectric materials. The challenge here is to reduce the high thermal conductivity of silicon and to realize high and homogeneous carrier concentration for high power factor. The thermal conductivity is reduced by forming nanocrystalline structures by sintering silicon crystal nanoparticles. Prior to developing the actual material, we investigated the potential controllability of thermal conductivity by directly measuring the interfacial thermal conductance at sintered interfaces in a 2D-model experiment, and relating it to thermal conductivity of nanocrystalline structures using the multiscale phonon-transport calculations. In addition, high and homogeneous carrier concentration is realized by using doped nanoparticles of several nanometers in diameters synthesized by plasma-enhanced chemical vapor deposition. The obtained bulk silicon thermoelectric material exhibits very low thermal conductivity and promising figure of merit.