摘要
A thermoelectric generator (TEG) was fabricated on a flexible substrate by screen printing and pressured sintering techniques for low-temperature heat harvesting applications. The screen-printed Bi-Sb-Te (p-type) and Bi-Se-Te (n-type) films that are sintered at 345 °C under a pressure of 25 MPa show the respective thermoelectric power factor of 14.3 and 8.4 μW/cm⋅K 2 at room temperature. A planar TEG made of three pairs of Bi-Sb-Te and Bi-Se-Te thermoelements delivers an output power of 50 μW at a temperature difference of 54.9 °C. The flexible TEG shows no electrical degradation after 1000 cycles of bending in the longitudinal and transverse directions of the thermoelements. A directional heat collection design is proposed to maximize the heat supply area of planar TEGs. The fabricated TEG can attain a maximum output power density of 58.3 μW/cm 2 under a temperature difference of 5.7 °C with a graphite heat transmission layer attached to a heat source at the temperature of 39.8 °C. It can serve as a self-sustained power source for wearable electronics and sensing devices by harvesting thermal energy from environment or human body.