Jump to main content
Jump to site search


Bi2Se3 topological insulator at the 2D-limit: Role of halide-doping on Dirac point

Abstract

Topological insulators at the 2D-limit exhibit insulating bulk and conducting edge-states with Dirac point, which, at times, is within the energy gap and could be on either sides of Fermi energy. In this work, we demonstrate the method to tune energy of the Dirac edge-state by introducing halides as dopants in Bi2Se3. We chose halides to substitute the anion, so that, due to a higher atomic number (of iodine, for example) with respect to selenium, spin-orbit coupling parameter could be enhanced leading to a shift in Dirac point to become well-separated from the Fermi energy. With different halogens having atomic numbers on either sides of selenium’s, Dirac point could hence be tuned towards both directions. The dopants, due to their heterovalent nature with respect to selenide, introduced carriers in the lattice and thereby shifted the Fermi energy also. We have shown that the Dirac point with respect to Fermi energy could be correlated to the dopant’s atomic number and thereby the atomic-number-induced spin-orbit coupling parameter. Strains developed in the lattice due to a mismatch in effective ionic radii of dopants and the host anion affected distribution of band energies leaving the (distribution of) Dirac point unaffected due to its topologically-protected nature.

Back to tab navigation

Supplementary files

Publication details

The article was received on 24 Apr 2018, accepted on 08 Jun 2018 and first published on 08 Jun 2018


Article type: Paper
DOI: 10.1039/C8CP02604A
Citation: Phys. Chem. Chem. Phys., 2018, Accepted Manuscript
  •   Request permissions

    Bi2Se3 topological insulator at the 2D-limit: Role of halide-doping on Dirac point

    S. Khatun, H. Bhunia and A. J. Pal, Phys. Chem. Chem. Phys., 2018, Accepted Manuscript , DOI: 10.1039/C8CP02604A

Search articles by author

Spotlight

Advertisements