Enhancing the thermoelectric performance of nanostructured ZnSb by heterovalent bismuth substitution. (January 2022)

• Record Type: Journal Article
• Authors: Sidharth, D.; Srinivasan, Bhuvanesh; Nedunchezhian, A.S. Alagar; Thirukumaran, P.; Arivanandhan, M.; Jayavel, R.
• Is Part Of: Journal of physics and chemistry of solids. Volume 160(2022)
• Publication Date: 2022-01
• Subjects: ZnSb -- XRD -- HRSEM -- Percolation effect -- Bismuth -- Carrier density and power factor; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2021.110303
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: Eco-friendly Bi substituted ZnSb samples were prepared by a novel hydrogen decrepitation method, followed by consolidation using the cold pressing technique. The structural and morphological analysis of the samples have been carried out by XRD, FESEM and TEM. XRD analysis confirms the phase purity of the ZnSb sample. The presence of secondary phase of Bi was observed in the XRD patterns of Bi substituted Zn1-x Bix Sb (0.02 ≤ x ≤ 0.06) samples, probably due to low solid solubility limit of Bi in ZnSb alloy. FESEM and HRTEM images revealed the highly inter-connected grain structure and the grain sizes were in the range of 200 nm. The electrical resistivity and Seebeck coefficient values of Zn1-x Bix Sb samples were decreased compared to the pristine ZnSb sample. The power factor of Zn0.98 Bi0.02 Sb sample increased compared to pure sample. The thermal conductivity of Zn1-x Bix Sb alloys were increased with increasing Bi content (x). As a result, a high ZT of ~0.45 was achieved for Zn0.98 Bi0.02 Sb sample at 573 K compared to pure ZnSb (0.39). The experimental results demonstrated that bismuth substitution with optimum content is a promising approach to enhance the thermoelectric properties of ZnSb. Graphical abstract: Image 1 Highlights: Eco-friendly Zn1-x Bix Sb nanostructures were prepared by Hydrogen decrepitation Method. Structural and morphological properties of the samples were studied by XRD, FESEM and HRTEM. Electrical resistivity of the alloys decreased with Bi(x) content. Zn0.98 Bi0.02 Te shows the highest power factor of ~1000 microWm −1 κ −1 at 473 K compared to other samples. A high ZT is ~0.45 at 573 K with high power factor was achieved for Zn0.98 Bi0.02 Te alloy.