Properties of Bi2Se3 Single Crystals Doped with Fe Atoms

Iron-doped Bi 2 Se 3 single crystals (c Fe = 0 to 5.3 x 10 19 atoms cm -3 ) were prepared by a modified Bridgman method from elements of 5N purity. The obtained samples were characterized by measurements of reflectivity in the plasma-resonance frequency region, optical transmission in the IR region, Hall coefficient, electrical conductivity and the Seebeck coefficient at room temperature. The doping of Bi 2 Se 3 single crystals by iron leads to an increase in the concentration of free electrons. This effect is ascribed to the presence of point defects formed by ionized iron atoms entering interstitial positions in the crystal lattice of Bi 2 Se 3 .