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HL: Fachverband Halbleiterphysik
HL 36: Transport properties
HL 36.4: Talk
Thursday, March 30, 2023, 10:15–10:30, POT 151
Semiconductor to Semimetall Transition in Bi-based Core-Shell Nanowires — Maximilian Kockert1, Rüdiger Mitdank1, Mahni Müller1, Hongjae Moon2, Jongmin Kim2, Wooyoung Lee2, and •Saskia Fischer1 — 1Humboldt-Univ. zu Berlin, Germany — 2Yonsei Univ., Seoul, Korea
The full-thermoelectric characterization of individual core/shell Bi-based nanowires is presented. Compressive strain induced by a TiO2 shell can lead to a band opening increasing the absolute Seebeck coefficient by up to 30 percent compared to bulk at room temperature [1]. If the strain exceeds the elastic limit the semimetallic state is recovered due to the lattice relaxation. The influence of strain on the temperature dependence of the electrical conductivity, the absolute Seebeck coefficient and the thermal conductivity of bismuth/titanium dioxide (Bi/TiO2) nanowires with different diameters was measured and compared to bismuth (Bi) and bismuth/tellurium (Bi/Te) nanowires and bismuth bulk. Different nano-contacting methods are discussed.
[1] M. Kockert, et al., Nanoscale Advances 3 (2021) 263