Lanthanum doping of the high-temperature p -type thermoelectric material Yb14 Mn Sb11 enhances the figure of merit (zT) through carrier concentration tuning. This is achieved by substituting La3+ on the Yb2+ site to reduce the free hole concentration as expected from the change in valence. The high-temperature transport properties (Seebeck coefficient, electrical resistivity, Hall mobility, and thermal conductivity) of Yb13.6 La0.4 Mn Sb11 are explained by the change in carrier concentration using a simple rigid parabolic band model, similar to that found in Yb14 Mn1-x Alx Sb11. Together, use of these two dopant sites enables the partial decoupling of electronic and structural properties in Yb14 Mn Sb11 -based materials.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)