Metallic conduction through van der Waals interfaces in ultrathin Bi2Te3 films.
- Resource Type
- Article
- Authors
- Hatta, Shinichiro; Obayashi, Ko; Okuyama, Hiroshi; Aruga, Tetsuya
- Source
- Scientific Reports. 3/11/2021, Vol. 11 Issue 1, p1-8. 8p.
- Subject
- *BISMUTH telluride films
*VAN der Waals forces
*PHOTOELECTRON spectroscopy
*CONDUCTION bands
*THICKNESS measurement
- Language
- ISSN
- 2045-2322
While the van der Waals (vdW) interface in layered materials hinders the transport of charge carriers in the vertical direction, it serves a good horizontal conduction path. We have investigated electrical conduction of few quintuple-layer (QL) Bi 2 Te 3 films by in situ four-point probe conductivity measurement. The impact of the vdW (Te–Te) interface appeared as a large conductivity increase with increasing thickness from 1 to 2 QL. Angle-resolved photoelectron spectroscopy and first-principles calculations reveal the confinement of bulk-like conduction band (CB) state into the vdW interface. Our analysis based on the Boltzmann equation showed that the conduction of the CB has a long mean free path compared to the surface-state conduction. This is mainly attributed to the spatial separation of the CB electrons and the donor defects located at the Bi sites. [ABSTRACT FROM AUTHOR]