title: Defect-Engineered Heat Transport in Graphene: A Route to High Efficient Thermal Rectification.
abstract: Low-dimensional materials such as graphene provide an ideal platform to probe the correlation between thermal transport and lattice defects, which could be engineered at the molecular level. In this work, we perform molecular dynamics simulations and non-contact optothermal Raman measurements to study this correlation. We find that oxygen plasma treatment could reduce the thermal conductivity of graphene significantly even at extremely low defect concentration (∼ 83% reduction for ∼ 0.1% defects), which could be attributed mainly to the creation of carbonyl pair defects. Other types of defects such as hydroxyl, epoxy groups and nano-holes demonstrate much weaker effects on the reduction where the sp(2) nature of graphene is better preserved. With the capability of selectively functionalizing graphene, we propose an asymmetric junction between graphene and defective graphene with a high thermal rectification ratio of ∼ 46%, as demonstrated by our molecular dynamics simulation results. Our findings provide fundamental insights into the physics of thermal transport in defective graphene, and two-dimensional materials in general, which could help on the future design of functional applications such as optothermal and electrothermal devices.
authors.affiliation: Jiangsu Key Laboratory for Design and Fabrication of Micro-Nano Biomedical Instruments, School of mechanical engineering, Southeast University, Nanjing 211189, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Zhao
authors.affiliation: Applied Mechanics Laboratory, Department of Engineering Mechanics and Center for Nano and Micro Mechanics, Tsinghua university, Beijing 100084, China.
authors.forename: Yanlei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189, China.
authors.forename: Zhangting
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189, China.
authors.forename: Wenhui
authors.initials: W
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory for Design and Fabrication of Micro-Nano Biomedical Instruments, School of mechanical engineering, Southeast University, Nanjing 211189, China.
authors.forename: Kedong
authors.initials: K
authors.lastname: Bi
authors.affiliation: Graphene Research and Characterization Centre, Taizhou Sunano New Energy Co., Ltd. Taizhou 225300,China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liang
authors.affiliation: Jiangsu Key Laboratory for Design and Fabrication of Micro-Nano Biomedical Instruments, School of mechanical engineering, Southeast University, Nanjing 211189, China.
authors.forename: Juekuan
authors.initials: J
authors.lastname: Yang
authors.affiliation: Jiangsu Key Laboratory for Design and Fabrication of Micro-Nano Biomedical Instruments, School of mechanical engineering, Southeast University, Nanjing 211189, China.
authors.forename: Yunfei
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Applied Mechanics Laboratory, Department of Engineering Mechanics and Center for Nano and Micro Mechanics, Tsinghua university, Beijing 100084, China.
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189, China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Ni