Point defects in Pb-doped Sb2Te3 single crystals

Single crystals of Sh,Te, doped with Pb atoms (c(Pb) = 0-2.1 x 10(20) atoms /cm(3)) were characterized by the measurements of the reflectivity in the p lasma resonance frequency region, the Hall coefficient, the electrical cond uctivity, and the Seebeck coefficient. Measurements of the Hall coefficient for a series of Ph-doped Sb2Te3 crystals served to determine the concentra tion of holes as a function of the Ph content in the lattice. The obtained variation of the hole concentration is ascribed to the formation of substit utional defects Pb-Sb' and to the interaction of the Ph atoms entering into the lattice with anti-site defects and vacancies in the tellurium sublatti ce. Improved ideas on point defects in the Ph-doped Sb2Te3 single crystals are formulated in this paper. (C) 1999 Academic Press.