大规模支撑单层石墨烯热导率的温度依赖性

Temperature Dependence of Thermal Conductivity of Giant-Scale Supported Monolayer Graphene.

作者信息

Liu Jing, Li Pei, Xu Shen, Xie Yangsu, Wang Qin, Ma Lei

机构信息

College of New Materials and New Energies, Shenzhen Technology University, Shenzhen 518116, China.

School of Mechanical and Automotive Engineering, Shanghai University of Engineering Science, Shanghai 201620, China.

出版信息

Nanomaterials (Basel). 2022 Aug 15;12(16):2799. doi: 10.3390/nano12162799.

DOI:10.3390/nano12162799

PMID:36014664

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9415878/

Abstract

Past work has focused on the thermal properties of microscale/nanoscale suspended/supported graphene. However, for the thermal design of graphene-based devices, the thermal properties of giant-scale (~mm) graphene, which reflects the effect of grains, must also be investigated and are critical. In this work, the thermal conductivity variation with temperature of giant-scale chemical vapor decomposition (CVD) graphene supported by poly(methyl methacrylate) (PMMA) is characterized using the differential transient electrothermal technique (diff-TET). Compared to the commonly used optothermal Raman technique, diff-TET employs joule heating as the heating source, a situation under which the temperature difference between optical phonons and acoustic phonons is eased. The thermal conductivity of single-layer graphene (SLG) supported by PMMA was measured as 743 ± 167 W/(m·K) and 287 ± 63 W/(m·K) at 296 K and 125 K, respectively. As temperature decreased from 296 K to 275 K, the thermal conductivity of graphene was decreased by 36.5%, which can be partly explained by compressive strain buildup in graphene due to the thermal expansion mismatch.

摘要

过去的工作主要集中在微尺度/纳米尺度悬浮/支撑石墨烯的热性能上。然而，对于基于石墨烯的器件的热设计而言，反映晶粒效应的大尺度（~毫米）石墨烯的热性能也必须加以研究，且至关重要。在这项工作中，利用差分瞬态电热技术（diff-TET）对聚甲基丙烯酸甲酯（PMMA）支撑的大尺度化学气相分解（CVD）石墨烯的热导率随温度的变化进行了表征。与常用的光热拉曼技术相比，diff-TET采用焦耳加热作为热源，在这种情况下，光学声子和声学声子之间的温差得以缓解。由PMMA支撑的单层石墨烯（SLG）在296 K和125 K时的热导率分别测得为743±167 W/(m·K)和287±63 W/(m·K)。当温度从296 K降至275 K时，石墨烯热导率下降了36.5%，这部分可归因于热膨胀失配导致石墨烯中产生压缩应变。