Point and structural defects in Bi2PbxTe3 single crystals

The study of the doping process of Bi2Te3 by Pb atoms in wide range of lead concentration ((1.0–80.0) × 1018 cm− 3) revealed two distinct areas of influence of the incorporated Pb atoms on changes in free carrier concentration. While at lower concentration of incorporated Pb (up to 20 × 1018 Pb atoms cm− 3) the ratio of generated holes to one incorporated Pb atom — Δp/cPb — falls from value of 1.06 down to 0.55, at higher concentration ((20–80) × 1018 Pb atoms cm− 3) the value stays constant. The observed behaviour of seeming electrical inactivity of the incorporated Pb atoms is explained by a point defect model taking into account the interaction between the entering Pb atoms and native lattice defects of Bi2Te3 crystal structure.