Tuning the thermoelectric properties of chalcopyrite by Co and Se double substitution

Mukherjee, S and Ramakrishnan, A and Chen, K-H and Chattopadhyay, K and Suwas, S and Mallik, RC (2018) Tuning the thermoelectric properties of chalcopyrite by Co and Se double substitution. In: 63rd DAE Solid State Physics Symposium 2018, DAE-SSPS 2018, 18 - 22 December 2018, Hisar, Haryana.

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Abstract

Chalcopyrite (CuFeS2) is an earth abundant, non-toxic, thermoelectric (TE) material with a high Seebeck coefficient of -480μV K-1 at 300K. But its TE performance is hindered due to low electrical conductivity (∼29 S cm-1 at 300K) and high thermal conductivity (∼6.5 Wm-1K-1 at 300K). Pristine CuFeS2 and Co,Se substituted compounds were prepared by solid state method. Powder X-ray diffraction confirmed the formation of the CuFeS2 phase (ICSD#2518). The transport properties were measured between the temperature 350 and 673K. The Seebeck coefficient (S) was negative for the pristine sample indicating n-type conductivity. Due to the deficiency of copper in the substituted samples, minority charge carriers dominated, and S was ∼50μV K-1 from 350 to 550K. After 550K, S becomes negative indicating that electrons are the majority charge carriers. The electrical conductivity is higher for the substituted samples compared to the pristine. The total thermal conductivity (κ) followed a T-1 trend, for all the samples due to Umklapp scattering. The isovalent substitution of Se for S helped in reducing the κl. The figure of merit of 0.018 at 673K was obtained for the substituted samples which was higher than the pristine sample (∼0.008 at 673K).

Item Type:	Conference Paper
Publication:	AIP Conference Proceedings
Publisher:	American Institute of Physics Inc.
Additional Information:	The copyright for this article belongs to American Institute of Physics Inc.
Department/Centre:	Division of Interdisciplinary Sciences > Interdisciplinary Centre for Energy Research Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy) Division of Physical & Mathematical Sciences > Physics
Date Deposited:	17 Dec 2022 07:37
Last Modified:	17 Dec 2022 07:37
URI:	https://eprints.iisc.ac.in/id/eprint/78485

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