Electrical Transport Properties of Single Crystalline β-Zn4Sb3 Prepared by α-Sn Flux Method

Abstract

In this study, p-type single crystalline β-Zn4Sb3 thermoelectric materials with space group R\( {\bar{3}} \)c were successfully prepared using the α-Sn flux method based on the stoichiometric ratios of Zn4+xSb3Sn3 (x = 0, 0.2, 0.4, 0.6). All the crystal sizes were more than 5 mm. The prepared samples had high density and no microcracks. The powder x-ray diffraction patterns showed that all the samples were single phase. All single-crystal samples possessed good electrical transport performance. Compared with polycrystalline β-Zn4Sb3, the carrier mobility of the single crystals were significantly improved. Moreover, excess Zn improved the Seebeck coefficient of the material. The electrical conductivities of the samples were comparable with those obtained by the β-Sn flux method, whereas the Seebeck coefficient declined on the whole and the intrinsic conduction temperature decreased. The power factor of the sample with x = 0.2 is 0.82 × 10−3 W m−1 K−2 at 635 K, which exhibited the best electrical transport performance.