Use of quantum-well superlattices to obtain a high figure of merit from nonconventional thermoelectric materials

Abstract

Currently, the materials with the highest thermoelectric figure of merit (ZT) are one‐band materials. The presence of both electrons and holes lowers ZT, so two‐band materials such as semimetals are not useful thermoelectric materials. However, by preparing these materials in the form of two‐dimensional quantum‐well superlattices, it is possible to separate the two bands and transform the material to an effective one‐carrier system. We have investigated theoretically the effect of such an approach and our results indicate that a significant increase in ZT may be achieved. This result allows the possibility of using a new class of materials as thermoelectric refrigeration elements.