Nanobinders advance screen-printed flexible thermoelectrics

Abstract

Limited flexibility, complex manufacturing processes, high costs, and insufficient performance are major factors restricting the scalability and commercialization of flexible inorganic thermoelectrics for wearable electronics and other high-end cooling applications. We developed an innovative, cost-effective technology that integrates solvothermal, screen-printing, and sintering techniques to produce an inorganic flexible thermoelectric film. Our printable film, comprising Bi₂Te₃-based nanoplates as highly orientated grains and Te nanorods as "nanobinders," shows excellent thermoelectric performance for printable films, good flexibility, large-scale manufacturability, and low cost. We constructed a flexible thermoelectric device assembled by printable n-type Bi₂Te₃-based and p-type Bi_0.4Sb_1.6Te₃ films, which achieved a normalized power density of >3 μW cm^-2 K^-2, ranking among the highest in screen-printed devices. Moreover, this technology can be extended to other inorganic thermoelectric film systems, such as Ag₂Se, showing broad applicability.