Abstract: Metal chalcogenides have attracted interest due to their potential applications in diverse technologies, including electronics, optoelectronics, and thermoelectrics. Among efforts to synthesize metal chalcogenides, solution synthesis offers several potential advantages over other methods such as molecular beam epitaxy and  chemical vapor deposition. The benefits of solution synthesis methods include low synthesis temperatures, short synthesis times, and compatibility with large scale.

A one-pot solution synthesis method to growth tellurium nanowires was developed; other metal chalcogenides can be converted on the basis of this template. We further scale up the reaction to a 1-liter reactor and a high yield (>7 g per batch) is achieved, which enables us to sinter metal chalcogenide powder into disks with 1-cm diameter by spark plasma sintering and investigate their electrical and thermal properties.

This presentation will first describe a solution-phase synthesis of iron telluride nanostructures with reversible and reproducible switching behavior between p- and n-type conduction. A proof-of-concept thermally triggered p-n diode has been demonstrated. Second, a large-scale solution-phase synthesis method to synthesize silver telluride based on the tellurium nanowire template has also been developed. Its structural phase transition can be realized by a temperature or electrically driven method, which makes it a good candidate for thermal switch. Finally, I will introduce the use of the solid-liquid dispersion method to combine bismuth antimony telluride and lead telluride into a graded disk sample to improve their thermoelectric performance.