Mobilities and Concentrations of Charge Carriers in Polycrystalline Bi_0.87Sb_0.13 Films

Abstract

The carrier mobilities and concentrations of polycrystalline films of Bio,87Sbo.13 with thicknesses between 30 and 330 nm are presented and discussed in the temperature range between 80 and 360 K. They are calculated from the electrical conductivity as well as the low-field Hall and magnetoresistance coefficients in a magnetic field directed orthogonally to the film plane. An anisotropic two-carrier model is taken as a basis for the calculation.Die Ladungstragerbeweglichkeiten und -konzentrationen von polykristallinen Bi,,8,Sbo,l ,-Schichten mit Schichtdicken zwischen 30 und 330 nm werden fur Temperaturen zwischen 80 und 360 K berechnet und diskutiert. Die Berechnung stiitzt sich auf Messungen der spezifischen Leitfahigkeit sowie des Hall-und des Magnetowiderstandskoeffizienten im schwachen Magnetfeld, wobei das Magnetfeld senkrecht zur Schichtebene orientiert ist. Als Grundlage fur die Berechnung wird ein anisotropes Zweitragermodell angewendet.

Electronic properties of nano-structured bismuth-antimony materials

“…Polycrystalline Bi 1Àx Sb x lms were synthesized long ago by evaporation, even before the 1980s. 83 Völklein and Dillner studied (1990) the carrier mobilities and concentrations for polycrystalline Bi 0.87 Sb 0.13 lms with lm thickness 30-300 nm at 80-360 K. 84 In 2011, Rogecheva et al then synthesized the trigonal-orientated mosaic-single-crystal Bi 0.955 Sb 0.045 lms with lm thickness 10-300 nm, and studied the oscillations in the room temperature electrical conductivity, Seebeck coefficient, and Hall coefficient as a function of lm thickness. 10 It was observed that the electrical conductivity, Seebeck coefficient, Hall coefficient, and thermoelectric power factor all tend to increase with lm thickness in these samples, and oscillations were observed over a large range of lm thickness, as shown in Fig.…”

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

“…It has been found, that depending on the Sb concentration, the bulk alloys show semimetal or semiconducting behavior, with a maximum band gap at around 15% antimony concentration and a band overlap below 5% and above 30%. 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].…”