Electronic Transport Studies of Ag-doped Bi2Se3 Topological Insulator

TL;DR

This study investigates how silver doping affects the electronic transport and surface states of Bi2Se3 topological insulators through various experimental techniques, revealing changes in conductivity, carrier type, and surface state energy levels.

Contribution

It provides new insights into the effects of Ag doping on the electronic properties and surface states of Bi2Se3 topological insulators using combined transport and spectroscopic measurements.

Findings

Ag doping induces metallic behavior with a slope change above 200 K.

Magnetoresistance follows quadratic dependence at low fields, consistent with Kohler's rule.

The Dirac point shifts to higher binding energy (~0.12 eV) with Ag doping.

Abstract

The structural, magnetotransport, and angle-resolved photoemission spectroscopy (ARPES) of Ag-doped Bi2Se3 single crystals are presented. Temperature dependent resistivity exhibits metallic behavior with a slope change above 200 K for Ag-doped Bi2Se3. The magnetoresistance shows positive quadratic dependence at low fields satisfying Kohler's rule. Hall resistivity measurement shows that electrons are dominant charge carriers. Furthermore, these results agree well with the ARPES spectra observed at T = 20 K, where the Fermi level lies inside the bulk conduction band. The Dirac point of the topological surface states is shifted toward higher binding energy (~ 0.12 eV) for Ag-doped samples as compared to pristine Bi2Se3.