Synthesis and thermoelectric characterization of individual nanowires

Abstract

It has been suggested by theoretical calculations that the thermoelectric figure of merit of nanowires can be much higher than the bulk value because of quantum and classical size effects on electron and phonon transport in the nanowire. Recent advances in nanomaterials synthesis and characterization methods have enabled direct experimental investigation of the nanoscale size effects on thermoelectric properties. In this work, bismuth nanowires are synthesized by vapor deposition into the pores of anodic alumina membranes (AAMs) with variable pore sizes. The thermoelectric properties of individual Bi nanowires obtained from the AAMs were investigated using two types of microfabricated measurement devices. The presence of a highly stable bismuth oxide coating prohibited good electrical contact with the nanowire, but still allowed for thermal conductivity data to be obtained. In addition, theoretical modeling was used to obtain carrier concentration and carrier mobility from the measured Seebeck coefficient and electrical conductivity for indium antimonide and chromium disilicide nanowires.