Band Bending Inversion in Bi 2 Se 3 Nanostructures

Louis Veyrat (1) , Fabrice Iacovella (2) , Joseph Dufouleur (1) , Christian Nowka (1) , Hannes Funke (1) , Ming Yang (3) , Walter Escoffier (2) , Michel Goiran (2) , Barbara Eichler (1) , Oliver Schmidt (1) , Bernd Büchner (1) , Silke Hampel (1) , Romain Giraud (4, 1)

1 IFW Dresden - Leibniz Institute for Solid State and Materials Research
2 LNCMI-T - Laboratoire national des champs magnétiques intenses - Toulouse
3 EPHYSE - Écologie fonctionnelle et physique de l'environnement
4 LPN - Laboratoire de photonique et de nanostructures

Shubnikov–de Haas oscillations were studied under high magnetic field in Bi2Se3 nanostructures grown by chemical vapor transport, for different bulk carrier densities ranging from 3 × 1019 cm–3 to 6 × 1017 cm–3. The contribution of topological surface states to electrical transport can be identified and separated from bulk carriers and massive two-dimensional electron gas. Band bending is investigated, and a crossover from upward to downward band bending is found at low bulk density as a result of a competition between bulk and interface doping. These results highlight the need to control electrical doping both in the bulk and at interfaces in order to study only topological surface states.

Mots clés: topological insulators; chemical vapor transport; Shubnikov-de Haas oscillations; bismuth selenide; band bending

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Louis Veyrat, Fabrice Iacovella, Joseph Dufouleur, Christian Nowka, Hannes Funke, et al.. Band Bending Inversion in Bi 2 Se 3 Nanostructures. Nano Letters, 2015, 15 (11), pp.7503-7507. ⟨10.1021/acs.nanolett.5b03124⟩. ⟨hal-02051520⟩