Year: 2000
Type: article
Abstract: The present study summarizes a feasibility study of the influence of the graded indium profile that is set up by the diffusion of indium from an external source, on the transport properties of PbTe crystals.PbTe crystals were grown by Czochralski technique.The penetration profiles of indium, diffusing from an external gaseous source was determined using Seebeck coefficient measurements in PbTe doped preliminary by Na impurity.The Seebeck coefficient changed a sign as the indium concentration induced a change from p-type to n-type character.Doping by indium generates deep impurity states lying close to the edge of the conduction band.Electron concentration practically didnt change along PbTe<In> crystal while indium concentration changed from 3•10 19 to 5•10 20 cm -3 .The thermovoltage V of a PbTe crystal in which an In concentration profile had been established was determined up to temperature ≈600 °C (in this case temperature of the cold side was constant ≈50 °C).It was discovered that V increases linearly with increasing temperature difference.This effect is connected with practically constant value of Seebecks coefficient in a wide temperature range through stabilization (pinning) of Fermi level by producing a concentration gradient of In impurity in PbTe crystals.
Author: Z. Dashevsky
Institution: Ben-Gurion University of the Negev
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: diamond
Funder: Israel Science Foundation
OpenAlex ID: W3000656744