We report the thermoelectric properties of Cu4In x Sn1-x S4 (x = 0-0.02), which undergoes a first-order structural phase transition at ∼230 K. Substitution of In3+ for Sn4+ suppresses the phase transition temperature (T t). Indium substitution reduces the electrical resistivity, and degenerate conduction by the orthorhombic phase is observed. The Seebeck coefficient increases over the whole temperature range and a maximum value occurs in the monoclinic phase as a result of indium substitution. Thermal conductivity decreases as x increases, which enhances the dimensionless figure of merit, ZT. We therefore expect optimization of the chemical composition of indium-doped Cu4SnS4 to result in an even larger ZT value.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry