Structural optimization, interfacial contact, and transverse thermoelectric properties of Ag₂Te/Bi_0.5Sb_1.5Te₃ artificially tilted multilayer thermoelectric devices

Artificially tilted multilayer thermoelectric devices (ATMTDs) have attracted widespread attention due to their advantages of simple and stable structure. In this study, n-type Ag₂Te and p-type Bi_0.5Sb_1.5Te₃ (BiSbTe), as two typically excellent room-temperature thermoelectric materials, were used to assemble ATMTDs. The interface structure and chemical composition of Ag₂Te/BiSbTe ATMTDs were characterized and their transverse thermoelectric performance was evaluated. The results indicated that the interfacial diffusion and reaction at Ag₂Te/BiSbTe interface leads to the formation of AgSbTe₂ phase with thickness approximately 22 μm and the interface established an ohmic-type electrical contact with a small contact resistance. After structural optimization, the Ag₂Te/BiSbTe ATMTD with titled angle 45° and aspect ratio 3 exhibited a large transverse voltage of reaches 6.78 mV at a temperature difference of 80 K, reaching 91.1% of the theoretical value. This work demonstrates that Ag₂Te/BiSbTe ATMTDs possess a good interfacial contact and transverse thermoelectric performance without significant power loss, maintaining excellent power generation and thermal response properties.