A new thermoelectric Ag8SiSe6 argyrodite for room temperature application: sensitivity of thermoelectric performance to cooling conditions

Abstract

Current commercial thermoelectrics, like Bi₂Te₃-based compounds, generally include the expensive and toxic Te element, which hampers their large-scale thermoelectric applications in near room temperature conditions. In this work, a Ag₈SiSe₆ argyrodite compound, a new thermoelectric material as a potential candidate for Bi₂Te₃-based compounds, was fabricated by several synthesis processes. All the Ag₈SiSe₆-based thermoelectric bulks, exhibiting a density surpassing 95%, were successfully synthesized. The study investigated the impact of varying the quenching rate and techniques on Ag₈SiSe₆'s thermoelectric performance. Our results revealed a pronounced relationship between the quenching parameters and pivotal thermoelectric metrics, including the Seebeck coefficient, electrical conductivity, and thermal conductivity. By optimizing the quenching conditions, we achieved a notable enhancement in ZT values, peaking over 0.7. This paves the way for Ag₈SiSe₆ to be considered as a competitive substitute for traditional n-type Bi₂Te₃-based compounds in thermoelectric applications under proximate room temperature conditions.