Enhancing efficiency and power of quantum-dots resonant tunneling thermoelectrics in three-terminal geometry by cooperative effects

摘要

We propose a scheme of multilayer thermoelectric engine where {\em one}electric current is coupled to {\em two} temperature gradients inthree-terminal geometry. This is realized by resonant tunneling through quantumdots embedded in two thermal and electrical resisting polymer matrix layersbetween highly conducting semiconductor layers. There are two thermoelectriceffects, one of which is pertaining to inelastic transport processes (ifenergies of quantum dots in the two layers are different) while the otherexists also for elastic transport processes. {These two correspond to thetransverse and longitudinal thermoelectric effects respectively and areassociated with different temperature gradients.} We show that cooperationbetween the two thermoelectric effects leads to markedly improved figure ofmerit and power factor {which is confirmed by numerical calculation usingmaterial parameters. Such enhancement is robust against phonon heat conductionand energy level broadening. Therefore we demonstrated cooperative effect as anadditional way to effectively improve performance of thermoelectrics inthree-terminal geometry.