Beneficial Effect of Na2CO3 Additions on the Thermoelectric Performance of Melt-Route Cu2Se

Authors

Sheik Md Kazi Nazrul-Islam, University of Technology Sydney
Md Rezoanur Rahman, University of Wollongong
Al Jumlat Ahmed, University of Wollongong
Frank Fei Yun, University of Wollongong
David L. Cortie, University of Wollongong
Xiaolin Wang, University of Wollongong
Michael B. Cortie, University of Technology Sydney

Publication Name

Advanced Electronic Materials

Abstract

High-performance thermoelectric materials require simultaneous reduction of thermal conductivity and electrical resistivity, among other criteria. Here it is shown that the introduction of Na2CO3 into the melt-route fabrication process for the well-known thermoelectric Cu2Se has a beneficial and surprisingly strong effect. There is a significant enhancement in electrical conductivity which density functional theory calculations suggest may be due to the effect of Na and O doping in the Cu2Se matrix. There is also a 34% reduction in thermal conductivity which is likely due to a high density of defects causing scattering of phonons. Overall, however, there is only relatively a small change in Seebeck coefficient. A higher power factor of 12.6 µW cm−1 K−2 is achieved versus 8.8 µW cm−1 K−2 for standard Cu2Se. A very high value of zT of 2.3 is obtained at 804 K versus 1.1 for standard Cu2Se.

Open Access Status

This publication is not available as open access

Funding Number

DP180100645

Funding Sponsor

Australian Research Council