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arXiv · 0711.0010

Diameter-dependent thermopower of Bi nanowires

A. Nikolaeva·T. E. Huber·D. Gitsu·L. Konopko
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Abstract

We present a study of electronic transport in individual Bi nanowires of large diameter relative to the Fermi wavelength. Measurements of the resistance and thermopower of intrinsic and Sn-doped Bi wires with various wire diameters, ranging from 150-480 nm, have been carried out over a wide range of temperatures (4-300 K) and magnetic fields (0-14 T). We find that the thermopower of intrinsic Bi wires in this diameter range is positive (type-p) below about 150 K, displaying a peak at around 40 K. In comparison, intrinsic bulk Bi is type-n. Magneto-thermopower effects due to the decrease of surface scattering when the cyclotron diameter is less than the wire diameter are demonstrated. The measurements are interpreted in terms of a model of diffusive thermopower, where the mobility limitations posed by hole-boundary scattering are much less severe than those due to electron-hole scattering.

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A. Nikolaeva, T. E. Huber, D. Gitsu, L. Konopko. 2007-11-01. Diameter-dependent thermopower of Bi nanowires. https://doi.org/10.1103/physrevb.77.035422

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