摘要
基于高性能薄膜热电器件的环境能量收集对自供电智能可穿戴电子设备的发展具有重要意义。本文通过真空镀膜调控衬底沉积温度实现Bi0.5Sb1.5Te3薄膜热电材料性能大幅提升,同时获得一种制备高性能柔性面外型热电器件的方法。采用电子衍射和扫面电镜等对Bi0.5Sb1.5Te3薄膜材料的结晶度及微观结构进行了分析,并测试了材料的电导和塞贝克系数等热电性能。结果表明沉积温度为250℃下制备的Bi0.5Sb1.5Te3薄膜材料具有很高的结晶度且在(0 1 5)晶面择优取向,其功率因子在温度为27℃时,可达4.06 mW/m·K2,是室温制备薄膜功率因子的5.7倍。由于提高温度有利于有序晶面的产生从而实现载流子和迁移率的调控,进而提升了薄膜材料的热电性能。因此制备温度的调节是实现热电材料性能提升的有效途径。此外,通过掩膜技术制备了基于Bi0.5Sb1.5Te3薄膜材料面外型柔性热电器件,该器件在5 K温差下,可获得最大输出功率为7.04 μW,这为柔性自供电可穿戴智能电子器件的发展提供理论与实验基础。
Environmental energy harvesting based on high-performance thin-film thermoelectric devices is of great significance to the development of self-powered intelligent wearable electronic equipment. In this paper, the thermoelectric performance of Bi0.5Sb1.5Te3 thin films is greatly improved by control-ling the deposition temperature of the substrate using vacuum coating and a method for preparing high-performance flexible cross-plane thermoelectric devices is developed. The crystallinity and microstructure of Bi0.5Sb1.5Te3 thin films were analyzed by electron diffraction and scanning elec-tron microscopy, and the thermoelectric properties such as electrical conductivity and Seebeck co-efficient of the material were investigated. The results show that the Bi0.5Sb1.5Te3 thin films prepared at a deposition temperature of 250˚C have high crystallinity and preferential orientation on the (0 1 5) crystal plane, and its power factor can reach 4.06 mW/m·K2 at a temperature of 27˚C, which is 5.7 times the power factor of the film prepared at room temperature. Since increasing the temperature is conducive to the generation of ordered crystal planes, the regulation of carriers and mobility is realized, thereby improving the thermoelectric properties of the thin-film material. Furthermore, a cross-plane flexible thermoelectric device based on Bi0.5Sb1.5Te3 thin films was prepared by mask technology. The device can obtain a maximum output power of 7.04 μW under a temperature difference of 5 K, which provides theoretical and experimental basis for the development of flexible self-powered wearable intelligent electronic devices.
出处
《材料科学》
CAS
2021年第12期1244-1252,共9页
Material Sciences
