Thermoelectric figure of merit and maximum power factor in III–V semiconductor nanowires

The relative contributions of electronic and lattice effects to figure of merit enhancement are studied, for nanowires made of InSb, InAs, GaAs, and InP, as a function of nanowire thickness. The main thermoelectric magnitudes are computed in the bulk and nanowire cases by the exact solution of the Boltzmann transport equation. The lattice thermal conductivity is obtained by a full dispersions transmission function approach, using interatomic potentials for the system. An upper limit to the maximum power factor is obtained for narrow thickness. InSb nanowires stand out as the best choice for thermoelectric applications among the four compounds considered, while GaAs and InP are not expected to be suitable for practical applications.