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 Bi 2 Te 3 -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 Bi 2 Te 3 -based and p-type Bi 0.4 Sb 1.6 Te 3 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 Ag 2 Se, showing broad applicability.
Finding thermoelectric devices that are flexible for harvesting things such as body heat has been challenging. Chen et al . improved thermoelectric inks for screen printing large-scale, flexible sheets by combining nanoplatelets of bismuth-telluride with tellurium nanorods. Screen printing and sintering this ink improved the thermoelectric properties, allowing for the construction of devices showing a promising amount of energy harvesting. This strategy should work for other materials and provides a way to produce large-scale, flexible thermoelectrics. —Brent Grocholski