Low-Dimensional Thermoelectric Materials

In Chap. 2, the thermoelectric transport coefficients (Seebeck, α, resistivity, ρ, and thermal conductivity, λ) were defined and analyzed as if they were strictly bulk quantities. This assumption is not valid if boundaries significantly affect the transport of electric current or heat, which can result from overall sample dimensions or structural features. The topic of size effects has become important in thermoelectric materials research because theoretical and experimental enhancements of the dimensionless figure of merit zT have been reported for low-dimensional structures. This area of the field is developing rapidly, and most of the work mentioned here has been done since 1990. First, we discuss, though, a few important earlier developments that comprise a useful prologue to the more recent work that we outline here.