Fast and scalable preparation of tetrahedrite for thermoelectrics via glass crystallization

• Methods of tetrahedrite preparation are usually time-consuming and expensive.
• A Cu12Sb3.6Bi0.4S10Se3 glass was prepared by melt spinning.
• Crystallization of the Cu12Sb3.6Bi0.4S10Se3 glass at selected temperatures gives materials with high-content of tetrahedrite.
• The all preparation process takes less than one day.
• Room temperature electrical transport properties are similar to those of tetrahedrites prepared by other methods.

A Cu12Sb3.6Bi0.4S10Se3 glass was prepared by melt spinning and crystallized by heat treatments at selected temperatures, the total preparation procedure taking less than one day. The sample characterization by powder X-ray diffraction, scanning and transmission electron microscopy complemented with EDS indicate the formation of compact materials, with a tetrahedrite relative weight fraction higher than 90% when treated at temperatures close to the crystallization peaks (∼200° C). Selenium enters the tetrahedrite structure, while bismuth precipitates in submicron and nanosized spherical shape phases depleted in copper and enriched in antimony, sulfur and selenium (when compared with the matrix composition). The characterization of electrical transport properties (electrical resistivity and Seebeck coefficient) indicate a behavior similar to that obtained by other methods on Cu12Sb4S13, with a maximum power factor of ∼400 μW/K2m at room temperature.