(GeTe)_<i>x</i>–(Sb₂Te₃)_1–<i>x</i> phase‐change thin films as potential thermoelectric materials

Abstract

Abstract Phase‐change materials form a unique material class, characterized by a rather unusual combination of physical properties. Exhibiting fast crystallization and a large contrast in optical reflectivity and electrical conductivity between the amorphous and the crystalline state, they are ideally suited for non‐volatile data storage. Here, we present the thermoelectric properties of Ge 3 Sb 2 Te 6 and Ge 8 Sb 2 Te 11 phase‐change alloys measured between room temperature and 120 °C. Both systems display intrinsically high Seebeck coefficients and low thermal conductivities. While low electrical conductivities preclude the employment of Ge 3 Sb 2 Te 6 in thermoelectric applications, the GeTe rich Ge 8 Sb 2 Te 11 exhibits high ZT s of up to 0.7 in the temperature range investigated, which renders this alloy a potential p‐type thermoelectric material.