Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5460669 | Journal of Alloys and Compounds | 2017 | 27 Pages |
Abstract
In the present work, we have investigated the effect of Cu content (x) on the phase structure and thermoelectric transport properties of CuxS (x = 1.92, 1.94, 1.98) bulks fabricated by combining mechanical alloying and spark plasma sintering. From density functional theory calculations of the valence band energy levels, we hypothesized that favourable valence band alignments accelerate electrical transport and can be achieved by optimizing the molar ratio of Cu1.96S to Cu2S. Experimentally, the sample with x = 1.92 showed an improved electrical conductivity 538.7 Scmâ1 at 623 K and retained a good Seebeck coefficient, synergistically leading to a broad, high power factor ranging from 105.9 to 900.3 μWmâ1Kâ2. The highly-disturbed Cu ions give CuxS compounds an intrinsically low lattice thermal conductivity (â¼0.5 Wmâ1Kâ1), which endows a high ZT of 1.23 as x = 1.94 to this otherwise simple semiconductor. The results indicate that low-cost and non-toxic CuxS superionic compounds are promising thermoelectric materials.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Li-Jun Zheng, Bo-Ping Zhang, He-zhang Li, Jun Pei, Jia-Bing Yu,