Point Defects in Pb-Doped Sb2Te3 Single Crystals

Single crystals of Sb2Te3 doped with Pb atoms (cPb=0–2.1×1020atoms/cm3) were characterized by the measurements of the reflectivity in the plasma resonance frequency region, the Hall coefficient, the electrical conductivity, and the Seebeck coefficient. Measurements of the Hall coefficient for a series of Pb-doped Sb2Te3 crystals served to determine the concentration of holes as a function of the Pb content in the lattice. The obtained variation of the hole concentration is ascribed to the formation of substitutional defects PbʹSb and to the interaction of the Pb atoms entering into the lattice with anti-site defects and vacancies in the tellurium sublattice. Improved ideas on point defects in the Pb-doped Sb2Te3 single crystals are formulated in this paper.