Study on Thermal Conduction Mechanism of Graphene-Like Carbon Nitride Structure (C3N)

As a new graphene-based two-dimensional semiconductor material, C3N has attracted extensive attention from researchers due to its excellent mechanical and electronic properties.Whether there are differences in the phonon transport mechanism of different C3N structures remains to be further investigated.Therefore,four kinds of C3N with different patterns were constructed in this paper, and their thermal conduction mechanism was studied by the non-equilibrium molecular dynamics (NEMD) method. The research results show that:(1) Among the four patterns,the C3N (M3) with the perfect structure has the highest thermal conductivity,followed by M1,and the lowest thermal conductivity of M4.(2) Moreover,the thermal conductivity of C3N with different patterns has obvious size and temperature effects.When the sample length is short,the phonon transport is mainly ballistic transport,while diffusion transport dominates the heat transport when the sample length is further increased.As the temperature increases,Umklapp scattering dominates the heat transport,making the thermal conductivity and temperature show a 1/T trend.(3) Compared with the M3,the patterns of M1 and M4 have larger phonon band gaps,and their dispersion curves are further softened.At the same time,regardless of low-frequency or high-frequency phonons,localized features appear in t M1 and M4(especially the M4),which has a significant inhibitory effect on thermal conductivity.This paper provides an idea for better design of thermal management materials.