Ag 2 Se as a tougher alternative to n-type Bi 2 Te 3 thermoelectrics.

For half a century, only Bi 2 Te 3 -based thermoelectrics have been commercialized for near room temperature applications including both power generation and refrigeration. Because of the strong layered structure, Bi 2 Te 3 in particular for n-type conduction has to be texturized to utilize its high in-plane thermoelectric performance, leaving a substantial challenge in toughness. This work presents the fabrication and performance evaluation of thermoelectric modules based on n-type Ag 2 Se paring with commercial p-Bi 2 Te 3 . Ag 2 Se mechanically allows an order of magnitude larger fracture strain and thermoelectrically secures the module efficiency quite competitive to that of commercial one for both refrigeration and power generation within ± 50 K of room temperature, enabling a demonstration of a significantly tougher alternative to n-type Bi 2 Te 3 for practical applications.