Structural defects in Cu-doped Bi2Te3 single crystals

The relation between the concentration of free charge carriers and the concentration of copper atoms in Bi2Te3 single crystals doped with copper over a wide range of concentrations has been investigated, with the aim of clarifying the existence of inactive Cu ions. Changes in the concentration of free charge carriers arising from Cu-doping of the melt with that induced by electrochemical intercalation of copper are compared. Models of possible defect structures are proposed for both doped and intercalated single crystals of Bi2Te3.