A local resonance mechanism for thermal rectification in pristine/branched graphene nanoribbon junctions

作者：Chen, Xue-Kun^*; Liu, Jun; Xie, Zhong-Xiang; Zhang, Yong; Deng, Yuan-Xiang; Chen, Ke-Qiu^*

来源：Applied Physics Letters, 2018, 113(12): 121906.

DOI：10.1063/1.5053233

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Using non-equilibrium molecular dynamics simulations, we investigate thermal rectification (TR) in pristine/branched graphene nanoribbon (GNR) junctions. The results indicate that the TR ratio of such junctions can reach 470% under small temperature bias, which has distinct superiority over asymmetric GNR and many other junctions. Moreover, the TR ratio decreases rapidly as the applied temperature bias increases. It seems to be against common sense that the TR ratio generally increases with temperature bias. Phonon spectra analyses reveal that the observed phenomena stem from the local resonance of longitudinal phonons in branched GNR region under negative temperature bias. Furthermore, the influence of ambient temperature, system length, branch number, and defect density is studied to obtain the optimum conditions for TR. This work extends local resonance mechanism to GNR for thermal signal manipulation. Published by AIP Publishing.

• 出版日期2018-9-17
• 单位中南大学; 南华大学; 湖南大学; 湖南工学院