Semimetal–semiconductor transition in Bi1−xSbx alloy nanowires and their thermoelectric properties

The resistivity of ${\mathrm{Bi}}_{\text{1−x}}{\mathrm{Sb}}_x$ nanowire arrays exhibits complex variations as a function of Sb content $x$ and temperature $T$ due to the unique semimetal-to-semiconductor (SM–SC) transition experienced by the nanowires. Seebeck coefficient measurements show enhanced thermopower due to Sb alloying and the reduction in wire diameter. The theoretical model not only explains these transport measurements, but also suggests a useful technique to experimentally determine (i) whether the wire is semimetallic or semiconducting, (ii) the carrier concentration, and (iii) the conditions for the SM–SC transition.