QUANTUM CORRECTION-BASED MOLECULAR DYNAMICS INVESTIGATION OF THERMAL TRANSPORT IN 2D SINGLE-LAYER C3B AND C3N

LT Xiong and JF Wang and HQ Xie and ZX Guo, HEAT TRANSFER RESEARCH, 53, 41-60 (2022).

To calculate accurately the thermal conductivity, quantum correction is necessary when the system temperature is below its Debye temperature. The calculated Debye temperature is 371.6 K or 383.1 K, much above room temperature, for 2D single-layer graphene doped with N atoms (SLC3N) or with B atoms (SLC3B), respectively. Here we used the quantum-corrected nonequilibrium molecular dynamics (MD) simulation to investigate the in- plane thermal conductivity of SLC3N and SLC3B in a wide temperature range between 150 K and 500 K. The predictions between the quantum- corrected MD and the classical MD without quantum correction are quite different when the temperature is below the Debye temperature. The prediction by the classical MD decreases monotonically with increasing temperature and is always larger than that by the quantum correction. With quantum correction, the thermal conductivity increases with increasing temperature at low temperatures up to a turning point below or near the room temperature and then decreases with further increase of temperature. The in-plane thermal conductivity of perfect SLC3B is predicted as 418 Wmiddotm(-1middot)K(-1 )at 300 K with quantum correction, smaller than the counterpart of perfect SLC3N (694 Wmiddotm(-1)middotK(-1)). Two defective types, i.e., single vacancy (SV) or double vacancy (DV), exist in practical 2D graphene. It is found that the quantum-corrected in-plane thermal conductivity decreases with increasing defective ratio; and under the same defective ratio, the effect of the SV defect is severer than that of the DV defect. The thermal conductivity of SLC3N and SLC3B with 0.1%, 0.3%, and 0.5% DV defect ratios basically remains unchanged with the increase of temperature in the high temperature range from 400 K to 500 K.

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