SKM 2021 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 4: Poster
DS 4.18: Poster
Dienstag, 28. September 2021, 10:00–13:00, P
Electrical transport properties of Vanadium-doped Bi2Te2.4Se0.6 — Ch. Riha1, B. Düzel1, K. Graser1, •O. Chiatti1, E. Golias2, J. Sánchez-Barriga2, O. Rader2, O. Tereshchenko3, and S. F. Fischer1 — 1Novel Materials Group, Humboldt-Universität zu Berlin, 10099 Berlin, Germany — 2Helmholtz-Zentrum-Berlin für Materialien und Energie, 12489 Berlin, Germany — 3Physics Department, Novosibirsk State University, 630090 Novosibirsk, Russia
Transport in the topological surface states (TSSs) of topological insulators, such as Bi2Se3, can be masked by unintentional bulk doping.
The alloy Bi2Te2.4Se0.6 is a promising candidate to investigate TSSs, because in Bi2Te3−ySey materials bulk n-type doping tends to be suppressed.
In this work [1], single crystals of VxBi2−xTe2.4Se0.6, with x = 0.015 and 0.03, are grown by the Bridgman method.
Angle-resolved photoemission spectroscopy shows gapless TSSs for both Vanadium concentrations.
The resistivity, the Hall charge carrier density, and the mobility for temperatures from 0.3 to 300 K are strongly dependent on the Vanadium concentration, with carrier densities as low as 1.5×1016 cm−3 and mobilities as high as 570 cm2/Vs.
Below 10 K, resistivity, carrier density, and mobility are constant, as expected for gapless TSSs.
Also, the magnetoresistance shows for both Vanadium concentrations weak antilocalization, which is analyzed with the Hikami-Larkin-Nagaoka model and yields phase-coherence lengths of up to 250 nm for x = 0.015.
[1] C. Riha et al., Phys. Status Solidi B, 2000088 (2020)