Towards the practical realization of high-performance Ag₂Se-based thermoelectric coolers

Ag₂Se-based materials with promising room-temperature thermoelectric performance and excellent mechanical properties have been known for decades. However, the fabrication of the Ag₂Se-based devices toward the practical application of electronic cooling has seldom been reported. Herein, the synthesis of Ag₂Se material with a diameter of 25.4 mm was achieved. The homogeneous elemental distribution and similar thermoelectric properties demonstrate the high uniformity of the Ag₂Se sample. In addition, ~90 Ag/Ag₂Se/Ag legs can be obtained from a single Ag₂Se plate, and the interfacial contact resistivity of the Ag/Ag₂Se varies from 0.8 to 3.1 μΩ cm². Four thermoelectric devices based on n-type Ag₂Se and p-type (Bi, Sb)₂Te₃ have been fabricated, and they achieve a cooling temperature difference of ~56 K at the hot-side temperature of 300 K, demonstrating the great potential of Ag₂Se material for cooling applications.