Thinking Like a Chemist: Intuition in Thermoelectric Materials.
The coupled transport properties required to create an efficient thermoelectric material necessitates a thorough understanding of the relationship between the chemistry and physics in a solid. We approach thermoelectric material design using the chemical intuition provided by molecular orbital diagrams, tight binding theory, and a classic understanding of bond strength. Concepts such as electronegativity, band width, orbital overlap, bond energy, and bond length are used to explain trends in electronic properties such as the magnitude and temperature dependence of band gap, carrier effective mass, and band degeneracy and convergence. The lattice thermal conductivity is discussed in relation to the crystal structure and bond strength, with emphasis on the importance of bond length. We provide an overview of how symmetry and bonding strength affect electron and phonon transport in solids, and how altering these properties may be used in strategies to improve thermoelectric performance.
Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA.
Wolfgang G
WG
Zeier
Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Strasse 40, 01187, Dresden, Germany.
Alex
A
Zevalkink
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.
Zachary M
ZM
Gibbs
Institute of Condensed Matter and Nanosciences (IMCN), Université Catholique de Louvain, 1348, Louvain-la-Neuve, Belgium.
Geoffroy
G
Hautier
Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA. m-kanatzidis@northwestern.edu.
Mercouri G
MG
Kanatzidis
Department of Materials Science and Engineering, Northwestern University, Evanston, IL, 60208, USA. jeff.snyder@northwestern.edu.
G Jeffrey
GJ
Snyder
band convergence; electronic structures; thermal conductivity; thermoelectrics