Lattice dynamics investigations of phonon thermal conductivity of Si∕Ge superlattices with rough interfaces
Lattice dynamics investigations of phonon thermal conductivity of Si∕Ge superlattices with rough interfaces
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粗糙界面Si∕Ge超晶格声子热导率的晶格动力学研究
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
Gang Chen
中科院分区：
文献类型：
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作者：
S. Ren;W. Cheng;Gang Chen
利用晶格动力学模型计算了具有完整界面和粗糙界面的Si闪烁Ge超晶格的生长方向和面内方向的声子热导率。结果表明，当层厚较小时，奇数层和偶数层SL的热导率在两个方向上都存在波动。在两个方向上的热导率与粗糙的界面的硅闪烁锗SL被证明是远远低于SL与完美的界面。为了了解粗糙界面的影响，进一步计算并比较了均质合金的热导率。结果表明，在沿着面内方向，界面粗糙的超导体的热导率与无规合金的热导率相当，而在生长方向，其热导率低于无规合金的热导率。
Phonon thermal conductivities in both growth and in-plane directions of Si∕Ge superlattices (SLs) with perfect and rough interfaces are calculated by using a lattice dynamics model. In addition to the general trend, the results show that there exist fluctuations of thermal conductivity in both directions for SLs with even or odd number of layers when the layer thickness is small. Thermal conductivities in both directions of Si∕Ge SLs with rough interfaces are shown to be much lower than those of SLs with perfect interfaces. To understand the influences of rough interfaces, thermal conductivities of homogeneous alloy are further calculated and compared. The results show that along the in-plane direction, the thermal conductivity of SLs with rough interfaces is about the same as that of random alloy, while in the growth direction it is lower than that of the random alloy.