论述了热电材料低维化和器件小型化的发展趋势以及在航空航天领域的应用.利用磁控溅射的方法,在柔性衬底聚酰亚胺(PI)上制备了热电薄膜材料,并对其微观结构和性能进行了表征,结果表明:P型Bi-Sb-Te和N型Bi-Te-Se薄膜均表现出(015)的取向性.利用ANSYS有限元模拟软件热电耦合场分析单元对面内型薄膜热电制冷器进行了模拟,讨论了器件的工作电流和材料物性参数对器件制冷性能的影响,发现通过减小基底的厚度和热导率,可增大基底面内方向的热阻,实现热流沿热电臂的传输;基底的镂空设计和制冷区域高导热层的引入,有利于制冷温差的建立和制冷区域的均匀制冷,这些为薄膜型制冷器件的制备提供了指导.
Low dimensional thermoelectric materials and the trend of miniaturization of devices as well as the application in the field of aerospace were discussed. Then the thermoelectric thin film material was fabricated on the polymide (PI) flexible substrate using magnetron sputtering method. The microstructure and property of thin film materials were characterized. The results show that the P-type Bi-Sb-Te and N-type Bi-Te-Se all have a preferential growth of (015) plane. The numerical simulation was also conducted on the in-plane thin film thermoelectric cooler by ANSYS finite element simulation software. The effect of working current and material physical property parameter on the cooling performance was discussed. It reveals that increasing the thermal resistance of substrate in plane by the decrease of thermal conductivity and thickness benefits the directional thermal flow along the thermoelectric legs. Besides, the hollowed design of substrate and the introduction of high thermal conductive layer in cooling area facilitate the establishment of cooling temperature difference and the uniform cooling in the cooling area. These results provide guidance for the preparation of thin film devices.