Construction of a cement-rebar nanoarchitecture for a solution-processed and flexible film of a Bi2Te3/CNT hybrid toward low thermal conductivity and high thermoelectric performance

Solution processability and flexibility still remain major challenges for many thermoelectric (TE) materials, including bismuth telluride (Bi2Te3), a typical and commercially available TE material. Here, we report a new solution-processed method to prepare a flexible film of a Bi2Te3/single-walled carbon nanotube (SWCNT) hybrid, where the dissolved Bi2Te3 ion precursors are mixed with dispersed SWCNTs in solution and recrystallized on the SWCNT surfaces to form a cement-rebar-like architecture. The hybrid film shows an n-type characteristic, with a stable Seebeck coefficient of -100.00 +/- 1.69 mu V K-1 in air. Furthermore, an extremely low in-plane thermal conductivity of similar to 0.33 W m(-1) K-1 is achieved at 300 K, and the figure of merit (ZT) reaches 0.47 +/- 0.02. In addition, the TE performance is independent of mechanical bending. The unique cement-rebar-like architecture is believed to be responsible for the excellent TE performances and the high flexibility. The results provide a new avenue for the fabrication of solution-processable and flexible TE hybrid films and will speed up the applications of flexible electronics and energy conversion.

Automated summary

A new solution-processed method to prepare a flexible film of a Bi2Te3/single-walled carbon nanotube (SWCNT) hybrid has been reported, showing excellent thermoelectric performances and high flexibility. The hybrid film exhibits n-type characteristic, with stable Seebeck coefficient and extremely low thermal conductivity. This research paves the way for the fabrication of solution-processable and flexible TE hybrid films.