Chapter 2 - Thermoelectric Transport in Quantum Well and Quantum Wire Superlattices

In this chapter, we described a theoretical treatment of the electronic contribution to thermoelectric transport in superlattices that has been developed over 5 years. This work clarified the physical ingredients needed to understand the power factor. It gives a reliable description of this quantity, of its essential qualitative dependences on both structure and potential, and it also provides fully quantitative results. This understanding will guide choices of systems that have the greatest potential for high power factors, and it also makes possible quantitative predictions for specific systems. We noted that many of the essential qualitative featfures of the power factor can be understood on the basis of a relatively straightforward description based on the constant relaxation time approximation for carrier scattering but that fully quantitative results require a theory based on an inelastic carrier scattering treatment. We have also noted that an understanding of the lattice thermal conductivity of these systems is needed in order to describe their figures of merit and that progress is now being made in this direction.