Enhanced thermoelectric performance of Cu₃SbS₄ flower-like hierarchical architectures composed of Cl doped nanoflakes via an in situ generated CuS template

Abstract

In this work, CuSbS hierarchical flower-like microspheres composed of chlorine (Cl)-doped CuSbS nanoflakes are realized via a one pot solvothermal ion exchange reaction. The kinetic factors including the duration time, the ratio of source materials, and the KOH concentration, are systematically investigated. Using a suite of analytical techniques, including SEM, XRD and FTIR, the mechanism of the two stage in situ chemical transformation of CuS flower-like microspheres consisting of nanoflake intermediates to the target product CuSbS is elucidated. The difference in solubility between reactants and products (Ksp(CuS) > Ksp(CuSbS)) determines that the ion-exchange reaction from transition binary to ternary metal chalcogenides is favorable under the impetus of a thermodynamic driving force. In addition, the optical and enhanced thermoelectric transport properties are investigated. The results revealed that Cl-doped CuSbS exhibited an improved power factor, which was 8 times higher than that of undoped CuSbS at 500 K. The current study not only provides a facile and economical way to synthesize high-quality Cl-doped Cu-Sb-S three dimensional (3D) hierarchical nanostructures, but also opens up a new route for preparation of other I-V-VI multicomponent chalcogenide NCs, such as Cu-Bi-S and Cu-Pb-S systems, which would be difficult to obtain otherwise.

Thermodynamic study of a synthetic analog of the famatinite mineral - Cu3SbS4

“…Particularly, famatinite mineral is considered to be up-and-coming material for thin-film heterojunction solar cells owing to its direct optical band gap in the range of 0.4 -1.0 eV, high optical absorption co-efficient (α > 10 4 cm -1 ), and p-type electrical conductivity [9,10]. This compound with its reported dimensionless figure of merit 0.14 at 623 K is also a promising thermoelectric material [11,12]. There are numerous works dedicated to the synthesis and characterization of Cu3SbS4 microflowers [13], nanofibers [14], nanocrystals [15,16], and thin films [9,17,18].…”

Synthesis and characterization of Cu3SbS4 thin films grown by co-sputtering metal precursors and subsequent sulfurization

“…Cu 3 SbS 4 phase has a reported direct optical bandgap in the range of 0.4 eV to 1 eV, high optical absorption coefficient (a 4 10 4 cm À1 ) and p-type electrical conductivity. [17][18][19] Most of the reported work on Cu 3 SbS 4 is on materials only in the form of micro-structures [20][21][22] and nanostructures [23][24][25][26] synthesized by chemical routes. There are only few reports on the synthesis of Cu 3 SbS 4 in thin film form.…”

Two-dimensional copper based colloidal nanocrystals: synthesis and applications

“…166,167 The 2D shape of these materials stems from complex electronic transport behaviour. 168–170 The in-plane direction possesses a smaller effective mass for electronic transport than the out of plane direction, resulting in greater carrier transport. In the following sub-sections, we cover the range of technological applications of colloidal 2D Cu based NCs.…”