Temperature and thickness dependence of electrical and thermal transport coefficients of Bi_1–xSb_x films in an anisotropic, non‐degenerate two‐band model

Abstract

The thickness and temperature dependences of electrical and thermal transport coefficients (e.g. electrical conductivity, thermoelectric power, thermal conductivity) of Bil -,Sb, films are described by a non-degenerated two-band model, considering the anisotropic elliptical band structure (manyvalley model) of bulk Bil -,Sb,. The transport coefficients are measured in the temperature range 80 to 400 K on films with thicknesses 20 to 400 nm and the results are interpreted and discussed using the deduced relations.Die Schichtdicken-und Temperaturabhangigkeit elektrischer und thermischer Transportkoeffizienten (z. B. der elektrischen Leitfahigkeit, der Thermokraft, der Warmeleitfiihigkeit) von Bil -,Sb,-Schichten wird im Rahmen eines nicht entarteten Zweiband-Modells unter Berucksichtigung der anisotropen elliptischen Bandstruktur (many valley model) von massivem Bil -%Sb, beschrieben. Die Transportkoeffizienten werden im Temperaturbereich 80 bis 400 K an Schichten von 20 bis 400 nm Dicke gemessen, und die Ergebnisse werden mit den abgeleiteten Beziehungen interpretiert und diskutiert.

Temperature-dependent growth of pulsed-laser-deposited bismuth thin films on glass substrates

“…As indicated by Hoffman et al [24], due to the additional scattering at the sample surface, ordinary size effect (increase in resistivity) is seen when the mean free path of the charge-carrier (about 0.6 μm for Bi at room temperature [24]) is comparable with or greater than the sample thickness (about 25 nm). Comparing our results with those of the literature for similar film thickness, the electrical resistivity is of the same order but higher than most of the previous investigations [23,[31][32][33][34][35]. Boffoué et al [35] also observed the higher resistivity of bismuth films grown by PLD, and attributed this phenomenon to the low deposition temperature and the absence of post annealing.…”

Effects of Size Reduction on the Electrical Transport Properties of 3D Bi Nanowire Networks

“…This non‐monotonic behavior has been described also using classical size effects based on the models of Fuchs, Mayadas and Dingle, considering the scattering of charge carriers at the surface and at grain boundaries. [ 24–28,61 ] In the case of nanowire arrays and networks, due to the high density of contacted nanowires, the electrical resistance values of the networks are very small (≈μohm), significantly smaller than the resistances of cables and/or contacts (≈mohm). In addition, since the exact number of connected wires is unknown, only relative values with respect to the resistance at 280 K can be provided.…”

Thickness and temperature dependent thermoelectric properties of Bi87Sb13 nanofilms measured with a novel measurement platform

“…Several years ago, Völklein et al published an extensive experimental study on Bi 1−x Sb x thin films with varying stoichiometry and thickness, in order to investigate their influence on the band structure and thermoelectric properties [23][24][25]. The results have been discussed in the framework of a previously proposed anisotropic non-degenerate two-band model, which can be found here [26]. Next to the unique thermoelectric behavior, recent investigations of nanostructured Bi 1−x Sb x alloys highlighted some further important topics like the experimentally investigation of topological insulators [27,28], possible revelation of a three-dimensional Dirac semimetal [29] or charge quantum Hall fractionalization [30].…”