Low-temperature sintering of Ag nanoparticles for high-performance thermoelectric module design

To facilitate the development of thermoelectric modules for various operating temperature ranges, a connection technology that is suitable for heat-sensitive thermoelectric materials and capable of realizing both low-temperature connections and high-temperature service is required. Here we use low-temperature sintering of silver nanoparticles as an approach to connect the electrode and metallization layer of low- (Bi₂Te₃-based), medium- (PbTe-based) and high-temperature (half-Heusler-based) thermoelectric modules. Owing to the low melting point of Ag nanoparticles and the high stability in the sintered bulk, the processing temperature of the module is decoupled from the operating temperature, avoiding welding thermal stress. We demonstrate a conversion efficiency of ~11% at the temperature difference of 550 K for the PbTe-based module. Additionally, the module’s performance remains nearly unchanged throughout thermal cycling between hot-side temperatures of 593 and 793 K for 50 cycles. Our work accelerates the development of advanced modules for thermoelectric power generation.