基于微纳结构的制冷器  

Microcooler based on micro-nanostructures

作　　者：陈云飞[1] 

机构地区：[1]东南大学机械工程学院,南京210096

出　　处：《东南大学学报（自然科学版）》2006年第3期356-360,共5页Journal of Southeast University：Natural Science Edition

基　　金：国家重点基础研究发展计划(973计划)资助项目(2006CB300404);国家高技术研究发展计划(863计划)资助项目(2003AA404160);国家自然科学基金资助项目(50276011;50275026;50475077);教育部博士点基金资助项目(20050286019);江苏省自然科学基金资助项目(BK2002060;BK2005063)

摘　　要：采用分子动力学模型对纳米结构的导热系数进行了计算.计算结果表明,在硅纳米线结构中,纳米结构的热传导系数的降低不仅是由于边界散射的增强,同时,声子色散曲线的变化使得声子群速度降低,造成不同波带能量差减小,从而强化了U散射过程,导致热传导系数进一步降低.在理论研究的基础上,采用微加工工艺在1.2μm厚的Ⅲ-Ⅴ族InGaAs/InGaAsP超晶格薄膜上加工出截面积为50μm×50μm热离子制冷器.实验结果表明,在环境温度30℃时,制冷器可获得最大2℃温差.数值模拟结果表明,接触电阻制约了器件性能的提升,如不考虑这个非理想因素,器件的最大制冷温差可达到10℃.Molecular dynamics simulation methods are used to simulate phonon transport in nanostructures. It is demonstrated that phonon behaves in different style when it transports in nanostructures and in bulk materials due to size confinement effects. The reduction of the lattice thermal conductivity of nanostructures is not only caused by the strong boundary scattering processes but also done with the modification of the phonon dispersion relation for nanostructures. In a Si nanowire, the modification of the phonon dispersion relation causes the decrease of the phonon group velocity and the reduction of band energy gap, which increases the U scattering probability that results in a further reduction of lattice thermal conductivity. For mismatched superlattice structures, the interface diffused scattering limits the phonon mean free path. A thermoionic microcooler based on InGaAs/ InGaAsP superlattice substrate is fabricated with a unit size of 50 μm × 50 μm. Experimental results demonstrate that a maximum temperature difference of 2 K is realized in this cooler, if the contact resistance can be further decreased, simulation results predict that 10K temperature difference is possible for such cooler.

关 键 词：微制冷器 超晶格 声子 纳米结构 

分 类 号：TB61[一般工业技术—制冷工程]