石墨烯/Bi_(0.5)Sb_(1.5)Te_(3)柔性热电薄膜及其面内散热器件的设计制备与性能评价

Design,fabrication and performance evaluation of graphene/Bi_(0.5)Sb_(1.5)Te_(3) flexible thermoelectric films and in-plane heat dissipation devices

基于柔性热电薄膜制冷的面内散热技术有望为电子器件高效面内散热提供解决方案,但柔性热电薄膜电输运性能太低和面内散热器件结构设计困难严重制约了该技术在电子元器件散热中的应用.本文通过在环氧树脂/Bi_(0.5)Sb_(1.5)Te_(3)柔性热电薄膜中掺入具有同时调控电热输运行为功能的石墨烯,发现不仅有助于Bi_(0.5)Sb_(1.5)Te_(3)晶粒沿(000l)择优取向,而且还提供了载流子快速传输通道,石墨烯/Bi_(0.5)Sb_(1.5)Te_(3)柔性热电薄膜的载流子浓度和迁移率同时显著增大;石墨烯掺入量为1.0%的柔性热电薄膜室温最高功率因子达到1.56 mW/(K^(2)·m),与环氧树脂/Bi_(0.5)Sb_(1.5)Te_(3)柔性热电薄膜相比提高了71%,其最大制冷温差提高了1倍.利用这种高性能石墨烯/Bi_(0.5)Sb_(1.5)Te_(3)柔性热电薄膜制冷,设计并制备出了级联结构高效面内散热器件,发现该器件可以将热量从热源区逐级传输至散热区,实现热源区温度下降1.4—1.9℃,展现出了高效稳定的面内散热能力.

In-plane heat dissipation technology based on flexible thermoelectric film cooling is expected to provide a solution to efficient in-plane heat dissipation of electronic devices.However,the low electrical transport performance of flexible thermoelectric films and the difficulty in designing the structure of in-plane heat dissipation device seriously restrict the applications of this technology in heat dissipation of electronic devices.In this work,an epoxy/Bi_(0.5)Sb_(1.5)Te_(3) flexible thermoelectric film is incorporated with graphene which can simultaneously regulate the electrical and thermal transport behaviors.It is found that the incorporating of graphene not only contributes to the preferential orientation of Bi_(0.5)Sb_(1.5)Te_(3) grains along(000l),but also provides a fast carrier transport channel.The carrier concentration and mobility of graphene/Bi_(0.5)Sb_(1.5)Te_(3) flexible thermoelectric film are simultaneously increased.Comparing with the epoxy/Bi_(0.5)Sb_(1.5)Te_(3) flexible thermoelectric film,the highest power factor of the flexible thermoelectric film with 1.0% graphene at room temperature reaches 1.56 mW/(K~2·m),increased by 71%,while the cooling temperature difference is doubled.Using this high-performance graphene/Bi_(0.5)Sb_(1.5)Te_(3) flexible thermoelectric film cooling,a cascade structure high-efficiency in-plane heat dissipation device is designed and fabricated.The device can dissipate heat from the heat source area to the heat dissipation area step by step and reduce the temperature of the heat source area by 1.4–1.9 ℃,showing an efficient and stable in-plane heat dissipation capability.