Atomic and electronic structure of a Rashba p-n junction at the BiTeI surface

Cédric Tournier-Colletta (1) , Gabriel Autès (2) , Bertrand Kierren (3) , Philippe Bugnon (1) , Helmuth Berger (1) , Yannick Fagot-Révurat (3) , Oleg V Yazyev (2) , Marco Grioni (1) , Daniel Malterre (3)

1 Institute of Condensed Matter Physics [Lausanne]
2 EPFL - Ecole Polytechnique Fédérale de Lausanne
3 IJL - Institut Jean Lamour

The non-centro-symmetric semiconductor BiTeI exhibits two distinct surface terminations that support spin-split Rashba surface states. Their ambipolarity can be exploited for creating spin-polarized p-n junctions at the boundaries between domains with different surface terminations. We use scanning tunneling microscopy (STM) and spectroscopy (STS) to locate such junctions and investigate their atomic and electronic properties. The Te- and I-terminated surfaces are identified owing to their distinct chemical reactivity and an apparent height mismatch of electronic origin. The Rashba surface states are revealed in the STS spectra by the onset of a van Hove singularity at the band edge. Eventually, an electronic depletion is found on interfacial Te atoms, consistent with the formation of a space-charge area in typical p-n junctions.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Cédric Tournier-Colletta, Gabriel Autès, Bertrand Kierren, Philippe Bugnon, Helmuth Berger, et al.. Atomic and electronic structure of a Rashba p-n junction at the BiTeI surface. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2014, 89 (8), pp.085402. ⟨10.1103/PhysRevB.89.085402⟩. ⟨hal-01273339⟩