title: Length-dependent thermal transport in one-dimensional self-assembly of planar π-conjugated molecules.
abstract: This work reports a thermal transport study in quasi-one-dimensional organic nanostructures self-assembled from conjugated planar molecules via π-π interactions. Thermal resistances of single crystalline copper phthalocyanine (CuPc) and perylenetetracarboxylic diimide (PTCDI) nanoribbons are measured via a suspended thermal bridge method. We experimentally observed the deviation from the linear length dependence for the thermal resistance of single crystalline β-phase CuPc nanoribbons, indicating possible subdiffusion thermal transport. Interestingly, a gradual transition to the linear length dependence is observed with the increase of the lateral dimensions of CuPc nanoribbons. The measured thermal resistance of single crystalline CuPc nanoribbons shows an increasing trend with temperature. However, the trend of temperature dependence of thermal resistance is reversed after electron irradiation, i.e., decreasing with temperature, indicating that the single crystalline CuPc nanoribbons become 'amorphous'. Similar behavior is also observed for PTCDI nanoribbons after electron irradiation, proving that the electron beam can induce amorphization of single crystalline self-assembled nanostructures of planar π-conjugated molecules. The measured thermal resistance of the 'amorphous' CuPc nanoribbon demonstrates a roughly linear dependence on the nanoribbon length, suggesting that normal diffusion dominates thermal transport.
authors.affiliation: Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong Special Administrative Region, China. dyxu@mae.cuhk.edu.hk and Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, 518057, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Tang
authors.affiliation: Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong Special Administrative Region, China. dyxu@mae.cuhk.edu.hk and Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, 518057, China.
authors.forename: Yucheng
authors.initials: Y
authors.lastname: Xiong
authors.affiliation: Institut für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 6, 12489 Berlin, Germany.
authors.forename: Fengshuo
authors.initials: F
authors.lastname: Zu
authors.affiliation: School of Mechanical Engineering and Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, Southeast University, Nanjing, 211189, China. yangjk@seu.edu.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong Special Administrative Region, China. dyxu@mae.cuhk.edu.hk and Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, 518057, China.
authors.forename: Xiaomeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong Special Administrative Region, China. dyxu@mae.cuhk.edu.hk and Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, 518057, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fu
authors.affiliation: Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China.
authors.forename: Jiansheng
authors.initials: J
authors.lastname: Jie
authors.affiliation: School of Mechanical Engineering and Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, Southeast University, Nanjing, 211189, China. yangjk@seu.edu.cn.
authors.forename: Juekuan
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong Special Administrative Region, China. dyxu@mae.cuhk.edu.hk and Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, 518057, China.
authors.forename: Dongyan
authors.initials: D
authors.lastname: Xu