Thermopower enhancement in lead telluride nanostructures

Abstract

We demonstrate an enhancement in the thermopower of PbTe nanostructures with grain sizes on the order of $30--50\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$, relative to bulk. The enhancement is similar in magnitude to that reported in the literature for $\mathrm{Pb}\mathrm{Te}∕\mathrm{Pb}{\mathrm{Se}}_{x}{\mathrm{Te}}_{1\ensuremath{-}x}$ quantum dot superlattices. We provide proof, based on measurements of the transverse Nernst effect, that the enhancement has its origin in electron energy filtering induced by an alteration of the scattering mechanism.