Nanoscale Thermal Transport in 2D Nanostructures from Cryogenic to Room Temperature
Nanoscale Thermal Transport in 2D Nanostructures from Cryogenic to Room Temperature
复制标题
DOI：
10.1002/aelm.201900331
复制
发表时间：
2019-08
影响因子：
6.2
通讯作者：
C. Evangeli;J. Spièce;S. Sangtarash;A. Molina‐Mendoza;M. Mucientes;T. Mueller;C. Lambert;H. Sadeghi;O. Kolosov
中科院分区：
文献类型：
--
作者：
C. Evangeli;J. Spièce;S. Sangtarash;A. Molina‐Mendoza;M. Mucientes;T. Mueller;C. Lambert;H. Sadeghi;O. Kolosov
报道了用纳米扫描热显微镜（SThM）测量二维结构从低温到室温的输运，分辨率低于30 nm。SThM的这种新颖的低温操作将样品的温度范围扩展到150 K，从而清楚地了解2D纳米结构的纳米特性，并支持在剥离的石墨烯的分离区域的边缘处的弹道传输贡献的模型，这导致分离材料的尺寸依赖性热阻。在150-300 K的温度范围内，通过添加MoS 2顶层，SiO2上的石墨烯的热阻增加了一个数量级，为使用货车德瓦尔斯（vdW）材料提高热电应用的效率提供了途径。密度泛函理论计算表明，这种增加源于声子输运过滤层之间的弱vdW耦合和MoS 2和石墨烯层之间的振动失配。
Nanoscale scanning thermal microscopy (SThM) transport measurements from cryogenic to room temperature on 2D structures with sub 30 nm resolution are reported. This novel cryogenic operation of SThM, extending the temperature range of the sample down to 150 K, yields a clear insight into the nanothermal properties of the 2D nanostructures and supports the model of ballistic transport contribution at the edge of the detached areas of exfoliated graphene which leads to a size‐dependent thermal resistance of the detached material. The thermal resistance of graphene on SiO2 is increased by one order of magnitude by the addition of a top layer of MoS2, over the temperature range of 150–300 K, providing pathways for increasing the efficiency of thermoelectric applications using van der Waals (vdW) materials. Density functional theory calculations demonstrate that this increase originates from the phonon transport filtering in the weak vdW coupling between the layers and the vibrational mismatch between MoS2 and graphene layers.