Improved performance in Mg3Sb2/Sb hybrid films for thermoelectric generation

Mg3Sb2-based bulk materials show great potential in both waste-heat recovery and cooling applications because of their excellent thermoelectric performance. But for the Mg3Sb2-based thermoelectric films, few efforts are devoted to it. Here, the p-type Mg3Sb2-based thermoelectric films have been successfully fabricated using the radio frequency magnetic sputtering method, which are composed of Mg3Sb2 and Sb phases. Interestingly, the ratio of Mg3Sb2 and Sb phases can be regulated by adjusting deposition temperature, where thermoelectric performance can be optimized, obtaining high power factor of 43.21 μV m−1 K−2 at 195 ℃. Furthermore, both Seebeck coefficient and electrical conductivity of Mg3Sb2 films are rarely decreased even after one month of exposure to air, demonstrating good stability. In order to further evaluate practicability, the output powers of Mg3Sb2/Sb films are measured at different temperature differences (ΔT), where an output voltage of ∼0.9 mV is achieved at ΔT of 31 ℃. In particular, the output power is basically consistent in the periodic cycle measurement, further implying a good stability. This work can provide a new thinking, enlightening more researchers to focus on the Mg3Sb2-based low-dimensional materials, and promoting its applications.