Thermoelectric investigation of bismuth nanowires

Abstract

An enhanced thermoelectric figure of merit, ZT, has been predicted for bismuth in the low-dimensional form of Bi nanowires. To obtain ZT experimentally, both the Seebeck coefficient, S, as well as the electrical resistivity, /spl rho/, must be determined, in addition to the thermal conductivity, not discussed in this work. A technique for measuring the electrical resistivity of individual Bi nanowires by a 4-point method was developed and carried out using electron-beam lithography techniques. A pattern of four electrodes was affixed on top of single Bi nanowires, and measurements of current versus voltage were made. Measurements of the Seebeck coefficient of arrays of Bi nanowires within an alumina template were also made. We report details of the experimental procedures as well as some preliminary results from measurements of the temperature dependence of both S and /spl rho/ for Bi nanowire arrays within an anodic alumina template.