Enhancing the performance of fully-scaled structure-adjustable 3D thermoelectric devices based on cold–press sintering and molding

Abstract

Abstract The growing concern over the global energy crisis strengthened the research on thermoelectricity. It would be logical to prepare practical thermoelectric device to effectively utilize various low-quality heat. In this study, the high-performance structure-adjustable 3D thermoelectric devices were fabricated by cold-press sintering and molding technologies. The thermoelectric figures of merit (ZT) of pressurized P and N–type materials reached the maximum of 1.09 and 0.5 at room temperature, respectively. The holes introduced by the binder and pressurization process reduced thermal conductivity and enhanced electrical properties. The in–depth influence on the thermoelectric devices was shown via simulation calculation. Fully-scaled thermoelectric devices suitable for various occasions were fabricated by one–time forming. The tandem of small and large arrayed thermoelectric devices respectively generated open–circuit voltages (Voc) of 584 mV and 573.8 mV and maximum output powers (Pmax) of 627.7 μW and 1.2 mW at 398.15 K. The Voc values of arched and annular thermoelectric devices were 265 mV and 332.1 mV at 398.15 K, respectively, and the Pmax values were 948.5 μW and 1.2 mW, respectively. On account of its good structure adjustability and high performance, thermoelectric devices fabricated will be broadly applied in solar–thermal conversion systems, automotive heat reclaimer and radioisotope thermoelectric generator.