Chalcogenide Glasses as Prospective Thermoelectric Materials

Despite the fact that glasses have interesting characteristics for thermoelectric (TE) applications, their potential as TE materials has only recently been tested. In a recent article, we focused on glasses based on the Ge20Te80 composition, which has a high Seebeck coefficient, S, showing that in Cu (x+y) Ge20-x Te80-y the power factor, S (2)/rho (where rho is the resistivity), strongly improves with increasing Cu concentration. Herein we report on the preparation of glasses in the Cu-Te-As system and their characterization by x-ray diffraction (XRD), differential scanning calorimetry (DSC), and measurements of rho and S. Our preliminary results show that the melt-spinning technique allows us to extend the Cu-Te-As glassy domain and leads to T (g) values that permit use of these glasses in applications up to 100A degrees C. A maximum S (2)/rho value of similar to 100 mu W K-2 m(-1) was obtained for the Cu30As15Te55 composition, confirming the potential of these glasses for TE applications.