Demonstration of electron filtering to increase the Seebeck coefficient   in ErAs:InGaAs/InGaAlAs superlattices
  In this letter, we explore electron filtering as a technique to increase Seebeck coefficient and the thermoelectric power factor of heterostructured materials over that of the bulk. We present a theoretical model in which Seebeck coefficient and the power factor can be increased in an InGaAs based composite material. Experimental measurements of the cross-plane Seebeck coefficient are presented and confirm the importance of the electron filtering technique to decouple the electrical conductivity and Seebeck coefficient to increase the thermoelectric power factor. 
J. M. O. Zide, D. Vashaee, G. Zeng, J. E. Bowers, A. Shakouri, A. C.   Gossard