Thermoelectric properties and stability of glasses in the Cu-As-Te system

Chalcogenide glasses and more importantly their glass-ceramics counterparts have been an interesting but very peculiar class of thermoelectric materials, with inherently low thermal conductivity (<0.3W/mK). In this study, we report on the fabrication of glasses in the ternary system Cu-As-Te (CuxAs55-xTe45 [5x20], Cu15As85-yTey [45y70], and Cu20As80-yTey [45y65]) by melt-quenching and subsequent spark plasma sintering treatment. Their thermal and structural properties have been studied by differential scanning calorimetry and Raman spectroscopy, leading to give insights into the structural evolution of the glassy matrix. Coupling this information with the analysis of their electrical transport properties allowed us to deepen further our understanding of the compositional effect on their thermoelectric properties, and indirectly how the evolution of their electronic band structure is at play. Despite exhibiting low ZT values by themselves, Cu-As-Te glasses may still be interesting candidates for thermoelectricity through partial crystallization for which knowing the relationship between composition and properties remains essential.