Millie Dresselhaus’ Legacy and Recent Advances in Thermoelectrics

Thermoelectric phenomena such as the Seebeck and the Peltier effects have been exploited
for solid-state power generation and cooling, but the efficiency values of thermoelectric devices
are limited by the low thermoelectric figure of merit of available materials, which is
proportional to the electrical conductivity and the square of the Seebeck coefficient but
inversely proportional to the thermal conductivity. These properties of a material in most cases
are strongly contradictory to each other, limiting advances in the field. In 1993, Millie
Dresselhaus published two pioneering papers on exploiting quantum size effects in 2D and 1D
quantum structures to improve thermoelectric figure of merit (PRB, 47, 12727; 47, 16631,
2013). These papers played a significant role in reinvigorating the field of thermoelectrics,
stimulating worldwide research in improving existing thermoelectric materials and searching
for new ones. Since then, the field has evolved significantly, and new ideas and concepts have
emerged and the materials figure of merit has seen significant improvements. This presentation
will start with a summary of Millie’s contributions to the field, followed by a critical review of
other successful ideas that have emerged, together with some discussion of novel electron and
phonon transport physics emerged in advancing materials.