Year: 1997
Type: article
Abstract: PbTe single crystals were prepared by the Bridgman method, where either Ag2Te or PbI2 was doped as the source material of silver and iodine. The hole concentration was successfully controlled in the range from 2.0×1024 to 9.0×1024 m−3 by doping 100 to 700 mol ppm Ag2Te, and from 3.5×1023 to 4.5×1024 m−3 by doping 100 to 650 mol ppm PbI2. In the case of PbI2 doping, the conduction type was changed at about 700 mol ppm PbI2, and the electron concentration was controlled in the range from 5.0×1022 to 5.0×1025 m−3 by doping 700 to 6000 mol ppm. Scattering factor r was estimated for both p- and n-type PbTe from the temperature dependence of Hall mobility. Thermal conductivity was calculated in terms of carrier concentration by evaluating the lattice (κph) and electronic (κel) thermal conductivities. The κel was estimated on the basis of Fermi integral by using observed data of α and r, where the κph was estimated to be 2.15 Wm−1 K−1 using the calculated κel value and the literature κ data for undoped PbTe. Maximum figure-of-merits (Zmax) of PbTe at 300 K were 1.21×10−3 K−1 for the n-type at n=2.76×1024 m−3 (2000 mol ppm PbI2) and 1.38×10−3 K−1 for p-type at p=2.34×1024 m−3 (200 mol ppm Ag2Te)
Institutions: Tohoku University, Tokyo Metropolitan University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2606511420