Recently, single crystals have been grown of a promising new thermoelectric material, ruthenium silicide (Ru2Si3). Although high figure of merit values have not actually been achieved as yet, the intrinsic properties of Ru2Si3 appear to be very favorable for thermoelectric applications. In this paper, the properties of undoped ruthenium silicide are extrapolated to heavily doped materials in order to provide some estimate of the thermoelectric figure of merit which might be achieved with optimal doping. In order to estimate the effect of doping several unverified assumptions have been made. First, is assumed that the carrier mobility of ruthenium silicide scales with doping level in the same way as the carrier mobility of silicon, decreasing substantially at the higher doping levels. It is assumed that the lattice component of the thermal conductivity does not vary doping level. All other effects of doping are accounted for using a simple, non-degenerate two band model for the transport properties. It is predicted that p-type ruthenium silicide may have a figure of merit more that 3 times the value of p-type silicon-germanium (SiGe) and that n-type ruthenium silicide may have a figure of merit 50 greater than n-type SiGe. While these estimates are subject to dangerously large uncertainties, they nevertheless are encouraging and provide some means for assessing the progress of experimental studies.
BT - Proceedings of the ninth symposium on space nuclear power systems C1 - Albuquerque, New Mexico (USA) DA - 1992/01/15/ LA - eng N2 -Recently, single crystals have been grown of a promising new thermoelectric material, ruthenium silicide (Ru2Si3). Although high figure of merit values have not actually been achieved as yet, the intrinsic properties of Ru2Si3 appear to be very favorable for thermoelectric applications. In this paper, the properties of undoped ruthenium silicide are extrapolated to heavily doped materials in order to provide some estimate of the thermoelectric figure of merit which might be achieved with optimal doping. In order to estimate the effect of doping several unverified assumptions have been made. First, is assumed that the carrier mobility of ruthenium silicide scales with doping level in the same way as the carrier mobility of silicon, decreasing substantially at the higher doping levels. It is assumed that the lattice component of the thermal conductivity does not vary doping level. All other effects of doping are accounted for using a simple, non-degenerate two band model for the transport properties. It is predicted that p-type ruthenium silicide may have a figure of merit more that 3 times the value of p-type silicon-germanium (SiGe) and that n-type ruthenium silicide may have a figure of merit 50 greater than n-type SiGe. While these estimates are subject to dangerously large uncertainties, they nevertheless are encouraging and provide some means for assessing the progress of experimental studies.
PB - AIP PY - 1992 SP - 338 EP - 342 EP - T2 - Proceedings of the ninth symposium on space nuclear power systems TI - Extrapolated thermoelectric figure of merit of ruthenium silicide UR - http://cvining.com/system/files/articles/vining/Vining-SNPP-1992.pdf VL - 246 ER -