SKM 2023 – scientific programme

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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