THERMAL CONDUCTIVITY OF A PRINTED THERMOELECTRIC FILM

We made composite films of Bismuth Telluride and Halide Perovskite at different sintering temperatures and characterized their thermoelectric properties. We aimed to improve thermoelectric properties through the reduction of effective thermal conductivity by using the interfacial thermal resistance between Halide Perovskite and Bismuth Telluride particles. Halide perovskite has been well investigated for a solar cell as one of the printable semiconductor materials. Here, we utilized Halide Perovskite as a thermoelectric material. The samples were prepared by printing and sintering the ink consisting of Bismuth Telluride powder produced by mechanical grinding and a precursor solution of Halide Perovskite. The thermoelectric performance was evaluated by a dimensionless figure-of-merit ZT at room temperature. The power factor of the composite films was higher than that of the pure Bismuth Telluride printed film, and the maximum value of power factor 205 μW/(m·K²) was obtained annealed at 350 °C. The thermal conductivity of the film was measured by bi-directional 3ω method. Compared the measured thermal conductivity of the composite film with the calculated thermal conductivity by simple models, we found that the thermal conductivity was greatly reduced by the high interfacial thermal resistance between Bismuth Telluride and Halide Perovskite. The proposed composite technique will be a promising method for improving both the thermoelectric properties and production cost performance.