Subhendra Dev Mahanti
Michigan State University, USA
Title: Recent advances and challenges in thermoelectrics
Biography
Biography: Subhendra Dev Mahanti
Abstract
Global energy issues have created a pressure to increase both the use of renewable sources of energy and the efficiency of current power generation and utilization. In the latter context thermoelectricity can play an important role in addressing the problems of energy utilization and management. The major challenge facing the thermoelectric research is to improve the efficiency which depends on dimensionless figure of merit (
is thermopower, 
is electrical conductivity,
is total thermal conductivity usually dominated by the phonons and 
is the operating temperature). To achieve higher efficiency, ideas like quantum confinement, electron crystal phonon glass, nanostructuring, hierarchical structures, energy filtering, low-dimensional charge transport created by highly anisotropic electronic band structure, etc. have impacted the field of thermoelectrics during the last several decades. In this talk I will review some of the recent advances in the field and discuss how ab initio theoretical calculations are contributing to and clarifying these ideas. Some of the systems I will discuss are (i) thermoelectric materials with intrinsically low thermal conductivity such as layered SnSe and bulk systems with effective superlattice structure Bi(CuSe)O and Sr(AgSe)F where CuSe(AgSe) layers are sandwiched between Bi-O (Sr-F) layers; (ii) 3-dimensional systems with highly anisotropic electronic bands as in Heusler systems. I will also briefly discuss recent work on computationally guided discovery of novel thermoelelctric materials for example, n-type Zintl compounds.