Validity of rigid band approximation of PbTe thermoelectric materials

The tuning of carrier concentration through chemical doping is very important for the optimization of thermoelectric materials. Traditionally, a rigid band model is used to understand and guide doping in such semiconductors, but it is not clear whether such an approximation is valid. This letter foc...

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Bibliographic Details
Main Authors: Yoshiki Takagiwa, Yanzhong Pei, Gregory Pomrehn, G. Jeffrey Snyder
Format: Article
Language:English
Published: AIP Publishing LLC 2013-07-01
Series:APL Materials
Online Access:http://dx.doi.org/10.1063/1.4809545
Description
Summary:The tuning of carrier concentration through chemical doping is very important for the optimization of thermoelectric materials. Traditionally, a rigid band model is used to understand and guide doping in such semiconductors, but it is not clear whether such an approximation is valid. This letter focuses on the changes in the electronic density of states (DOS) near the valence band maximum for different p-type dopants (Na, K, Tl, or vacancy on Pb site) maintaining the high symmetry of the NaCl structure. Na- and K-doped, and vacancy-introduced PbTe show a clear rigid-band like change in DOS unlike that concluded from supercell based calculations.
ISSN:2166-532X