Thermoelectric Properties of a Single Crystalline Ag2Te Nanowire

Silver chalcogenides have received much attention in potential thermoelectric materials research because of high carrier mobility and low effective mass. Among them, in Ag2Te, it was reported that the phase transition from monoclinic to cubic phase occurs at relatively low temperatures, so that extensive research for effective application using this material has been aroused. In this work, we investigated how 1-dimensional nanostructure affects the thermoelectric properties through as-synthesized single crystalline Ag2Te nanowires. Adopting well-defined thermoelectric MEMS device structure and transferring an individual Ag2Te nanowire, we measure electrical resistance and Seebeck coefficient as a function of temperature. When the phase changes frommonoclinic to cubic, the resistance increases, while absolute Seebeck coefficient value decreases. These results are compared with previous reports for Ag2Te bulk and film, suggesting the increased density of states of the carriers due to nanowire structure.