Quantitative understanding of 2D atomic layer interface thermal resistance (R) based on Raman characterization is significantly hindered by unknown sample-to-sample optical properties variation, interface-induced optical interference, off-normal laser irradiation, and large thermal-Raman calibration uncertainties. In this work, we develop a novel energy transport state resolved Raman (ET-Raman) to resolve these critical issues, and also consider the hot carrier diffusion, which is crucial but has been rarely considered during interface energy transport study. In ET-Raman, by constructing two steady heat conduction states with different laser spot sizes, we differentiate the effect of R and hot carrier diffusion coefficient (D). By constructing an extreme state of zero/negligible heat conduction using a picosecond laser, we differentiate the effect of R and material’s specific heat. In the end, we precisely determine R and D without need of laser absorption and temperature rise of the 2D atomic layer. Seven MoS₂ samples (6.6–17.4 nm) on c-Si are characterized using ET-Raman. Their D is measured in the order of 1.0 cm²/s, increasing against the MoS₂ thickness. This is attributed to the weaker in-plane electron–phonon interaction in thicker samples, enhanced screening of long-range disorder, and improved charge impurities mitigation. R is determined as 1.22–1.87 × 10^–7 K·m²/W, decreasing with the MoS₂ thickness. This is explained by the interface spacing variation due to thermal expansion mismatch between MoS₂ and Si, and increased stiffness of thicker MoS₂. The local interface spacing is uncovered by comparing the theoretical Raman intensity and experimental data, and is correlated with the observed R variation.

中文翻译：

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能量传输状态已解析拉曼，用于探测层状MoS _2中的界面能量传输和热载流子扩散

未知样品之间的光学特性变化，界面引起的光学干扰，不正常的激光辐照以及较大的热拉曼校准不确定性，严重阻碍了基于拉曼表征对2D原子层界面热阻（R）的定量理解。在这项工作中，我们开发了一种解决了这些关键问题的新​​型能量传输态拉曼光谱（ET-Raman），并考虑了热载流子扩散问题，该问题至关重要，但在界面能量传输研究中很少考虑。在ET拉曼光谱中，通过构造两个具有不同激光光斑尺寸的稳态热传导状态，我们区分了R和热载流子扩散系数（D）。通过使用皮秒激光器构造零/可忽略的热传导的极端状态，我们可以区分R的影响和材料的比热。最后，我们无需激光吸收和2D原子层的温度升高即可精确确定R和D。使用ET-拉曼光谱仪表征了c-Si上的七个MoS ₂样品（6.6-17.4 nm）。它们的D以1.0cm ² / s的量级测量，相对于MoS ₂厚度增加。这归因于在较厚的样品中较弱的面内电子-声子相互作用，增强了对远程无序性的筛选，并改善了电荷杂质的缓解。[R确定为1.22–1.87×10 ^–7 K·m ² / W，随MoS ₂厚度的增加而减小。这是由于由于MoS ₂和Si之间的热膨胀失配以及较厚的MoS _2的刚度增加而引起的界面间距变化而解释的。通过比较理论拉曼强度和实验数据可以发现局部界面间距，并且与观察到的R变化相关。