Enhancing thermoelectric performance of bismuth selenide films by constructing a double-layer nanostructure

A new nanostructure of double-layer thin films (DLTFs) has been introduced to Bi2Se3 as thermoelectric films through a facile one-step and low-temperature solution route. The Bi2Se3 DLTFs consist of a (001) orientational inner layer and a (110) orientational outer layer with controllable thicknesses. The controllable release of the precursor ion is critical to adjust the double-layer nanostructures. The maximum power factor of the Bi2Se3 DLTFs reaches 100 μW m−1 K−1, which is larger by 79% than the value for a single layer Bi2Se3 film.