Thermoelectric properties of P-type Sb2Te3 thick film processed by a screen-printing technique and a subsequent annealing process

•We report on thermoelectric properties of screen-printed Sb2Te3 thick film.•Subsequent annealing process determines thermoelectric properties of Sb2Te3 film.•Annealing in tellurium powder ambient contributes to tellurium-rich Sb2Te3 film.•Annealing in tellurium powder ambient enhances carrier mobility of Sb2Te3 film.

We herein report the thermoelectric properties of Sb2Te3 thick film fabricated by a screen-printing technique and a subsequent annealing process. Each step of the screen-printing fabrication process of Sb2Te3 thick film is described in detail. It was found that the subsequent annealing process must be carefully designed to achieve good thermoelectric properties of the screen-printed film. The results show that the annealing of the screen-printed Sb2Te3 thick film together with tellurium powder in the same process chamber significantly improves the carrier mobility by increasing the average scattering time of the carrier in the film, resulting in a large improvement of the power factor. By optimizing the annealing process, we achieved a maximum thermoelectric figure-of-merit, ZT, of 0.32 at room temperature, which is slightly higher than that of bulk Sb2Te3. Because screen-printing is a simple and low-cost process and given that it is easy to scale up to large sizes, this result will be useful for the realization of large, film-type thermoelectric devices.