On the Galvanomagnetic Properties and Thermoelectric Power of Ultrathin Films of the Bismuth–Antimony System on a Mica Substrate

• Published in: Semiconductors (Woodbury, N.Y.) N.Y.), 2022-05, Vol.56 (5), p.310-316
• Main Authors: Gerega, V. A., Suslov, A. V., Komarov, V. A., Grabov, V. M., Demidov, E. V., Kolobov, A. V.
• Format: Article
• Language: English
• Subjects: Alloys; Antimony; Antimony base alloys; Bismuth; Bismuth alloys; Converters; Dielectric films; Electric properties; Electromagnetism; Electronic properties; Magnetic Materials; Magnetism; Mica; Physics; Physics and Astronomy; Seebeck effect; Substrates; Thermoelectricity; Thickness; Thin films
• ISSN: 1063-7826; 1090-6479
• DOI: 10.1134/S1063782622050037

— Investigation of the electronic properties of ultrathin films of pure bismuth and bismuth–antimony alloys is of interest, since it is found that the conductivity increases with decreasing sample thickness. The results of experimental investigation of the structure, as well as of the electrical, galvanomagnetic, and thermoelectric properties of pure bismuth and Bi 1 –  x Sb x thin films ( x = 0.05 and 0.12) on a mica substrate in the thickness range of 10–30 nm are presented. An increase in the conductivity with decreasing thickness of the samples, which may be induced by the presence of topologically protected surface states, is found. It is shown that the features of this effect depend significantly on the band structure of alloys. The form of the temperature dependences of the Seebeck coefficient casts doubt on the fact that the surface states have a positive effect on the thermoelectric efficiency of thin bismuth–antimony films. However, the detection of positive thermoelectric power in Bi 0.88 Sb 0.12 samples may become an important factor in learning how to create the p  branch of thermoelectric converters.