Publication Date

8-2019

Department

Ames Laboratory; Chemistry

Campus Units

Ames Laboratory, Chemistry

OSTI ID+

1547182

Report Number

IS-J 10017

DOI

10.1016/j.jssc.2019.05.016

Journal Title

Journal of Solid State Chemistry

Volume Number

276

First Page

361

Last Page

367

Abstract

Layered tetrel pnictides have shown promise as thermoelectrics (TEs) due to their anisotropic crystal structure and weak van der Waals interactions between layers. The binary GeAs is a p-type semiconductor with a narrow indirect bandgap of 0.57 eV and a high Seebeck coefficient (∼250 μV/K at 300 K). This work probes the limits of the aliovalent substitutions of GeAs to modify charge carrier concentration. GaxGe1-xAs (x = 0.005, 0.01, and 0.02) and GeAs1-ySey (y = 0.01, 0.02, 0.03, and 0.05) samples were synthesized to study the structure-property relationships in this system. Hole doping of GeAs via Ga-substitution increases carrier concentration resulting in the decrease in both resistivity and Seebeck coefficient. Se-substituted samples show more complex behavior related to defect chemistry. Overall, the thermoelectric power factor (S2/ρ) was significantly enhanced (up to 89%) for Ga0.005Ge0.995As as compared to pristine GeAs.

DOE Contract Number(s)

AC02-06CH11357

Language

en

Publisher

Iowa State University Digital Repository, Ames IA (United States)

Available for download on Friday, May 15, 2020

Share

COinS