Measurements of the Thermal Resistivity of InAlAs, InGaAs, and InAlAs/InGaAs Superlattices
Measurements of the Thermal Resistivity of InAlAs, InGaAs, and InAlAs/InGaAs Superlattices
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DOI：
10.1021/acsami.8b17268
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发表时间：
2019-03-27
影响因子：
9.5
通讯作者：
Eriksson, M. A.
中科院分区：
文献类型：
--
作者：
Jaffe, G. R.;Mei, S.;Eriksson, M. A.
纳米器件的热管理工作必须考虑组成材料的热特性和连接它们的界面。目前尚不清楚合金/合金半导体超晶格如InAlAs/InGaAs是否具有比其组成合金更低的热导率。我们报告在室温下的InAlAs/InGaAs超晶格的横截面热阻率的测量结果，表明超晶格的热导率是由1.2-1.6的一个因素比组成的大块材料，取决于应变状态和组合物。我们表明，在这些超晶格中存在的额外的电阻可以通过改变晶格失配，从而在界面处的声子模式失配，通常假设为超晶格，但尚未实验验证，而不添加新的元素的层的原则，由2.5倍调谐。我们发现，在超晶格中的附加电阻并没有显着增加时，层厚度从4到2 nm的减少。我们还报告了250-1000 nm厚的未掺杂InGaAs和InAlAs薄膜的测量结果，这些薄膜与InP衬底晶格匹配，因为后者的热导率值没有公布，我们发现在22摄氏度时为2.24 +/- 0.09，这比广泛使用的估计值小2.7倍。
Thermal management efforts in nanoscale devices must consider both the thermal properties of the constituent materials and the interfaces connecting them. It is currently unclear whether alloy/alloy semiconductor super-lattices such as InAlAs/InGaAs have lower thermal conductivities than their constituent alloys. We report measurements of the crossplane thermal resistivity of InAlAs/InGaAs superlattices at room temperature, showing that the super-lattice resistivities are larger by a factor of 1.2-1.6 than that of the constituent bulk materials, depending on the strain state and composition. We show that the additional resistance present in these superlattices can be tuned by a factor of 2.5 by altering the lattice mismatch and thereby the phonon-mode mismatch at the interfaces, a principle that is commonly assumed for superlattices but has not been experimentally verified without adding new elements to the layers. We find that the additional resistance in superlattices does not increase significantly when the layer thickness is decreased from 4 to 2 nm. We also report measurements of 250-1000 nm thick films of undoped InGaAs and InAlAs lattice-matched to InP substrates, for there is no published thermal conductivity value for the latter, and we find it to be 2.24 +/- 0.09 at 22 degrees C, which is similar to 2.7 times smaller than the widely used estimates.