A new thermoelectric Ag8SiSe6 Argyrodite for room temperature application: its cooling conditions sensitivity of thermoelectric performance

The present commercial thermoelectrics like (BiSb)2Te3 compounds include expensive and toxic Te element, which hampers a large-scale thermoelectric application near room temperature. Ag8SiSe6 argyrodite compound, as a green and low cost thermoelectric material, is potential candidate for BiSbTe compounds. In this work, Ag8SiSe6 compounds were synthesized through a traditional melting process combined with a hot pressing densification, marking the first systematic investigation of their thermoelectric properties linking to different post-treatments. By designing the cooling rates of the ingots, a substantial improvement in the power factor has been attained, particularly in the sample quenched in water, due to a marked reduction in resistivity. To our knowledge, although a pure Ag8SiSe6 phase cannot be prepared by possible available fabrication method up to now the current methods, a high-performance thermoelectric material has been fabricated through the integration of ball milling treatment with the quenched ingot, achieving a peak ZT value of approximately 0.71 at 398 K.