退火条件对磁控溅射MgO-Ag3Sb-Sb2O4柔性薄膜热电性能的影响

MgAgSb是一种具有潜力且元素储量相对丰富的室温热电材料, 有望用于构建高性能可穿戴温差电池。本研究尝试在聚酰亚胺(PI)基底上磁控溅射制备MgAgSb薄膜, 并系统研究退火条件对其热电性能的影响。结果表明样品未形成纯相的MgAgSb柔性热电薄膜, 而是形成了由Ag₃Sb、MgO及Sb₂O₄多相组成的柔性薄膜, 其中Ag₃Sb起主要热电功能。不同气氛退火可以显著提升MgO-Ag₃Sb-Sb₂O₄ (Mg-Ag-Sb)柔性薄膜的热电性能, 其中真空处理性能最佳。在真空条件下, 随着退火温度升高, 柔性薄膜的热电性能呈现先增加后减少的趋势, 当退火温度为573 K时热电性能最佳, 室温附近功率因子达到74.16 μW∙m^-1∙K^-2。并且, 薄膜表现出较好的柔性, 弯曲900次后, 电导率仅变化了14%。本研究为MgAgSb柔性热电薄膜的制备及可穿戴应用提供了参考。

Effect of Annealing Conditions on Thermoelectric Properties of Magnetron Sputtered MgO-Ag3Sb-Sb2O4 Flexible Films

MgAgSb is a promising room temperature thermoelectric material with relatively abundant element reserves for the construction of high-performance wearable thermoelectric batteries. In this study, Mg-Ag-Sb thin films were prepared on polyimide (PI) substrates by using magnetron sputtering, and the effects of annealing conditions on their thermoelectric properties were systematically investigated. The results showed that the MgAgSb flexible thermoelectric film composed of MgO, Ag₃Sb and Sb₂O₄ multiphases instead of pure phase, in which Ag₃Sb played main role of thermoelectric function. Different annealing atmospheres significantly improved the thermoelectric properties of MgO-Ag₃Sb-Sb₂O₄ (Mg-Ag-Sb) flexible thin films, among which the vacuum treatment appeared the best performance. Under vacuum conditions, the thermoelectric properties firstly increased and then decreased with the annealing temperature increasing, and the best thermoelectric property was achieved when the annealing temperature was 573 K, with a power factor of 74.16 μW∙m^-1∙K^-2 near room temperature. Moreover, the film exhibited good flexibility, and the conductivity changed by only 14% after 900 bending times. This study provides a reference for the preparation of MgAgSb flexible thermoelectric films and their wearable applications.