Modulation of the thermal conductivity, interlayer thermal resistance, and interfacial thermal conductance of C2N

Abstract

C₂N, a novel 2D semiconductor with orderly distributed holes and nitrogen atoms, has attracted significant attention due to its possible practical applications. This paper investigates the in-plane thermal conductivity and interlayer thermal resistance of C₂N and the interfacial thermal conductance of in-plane heterostructures assembled by C₂N and carbonized C₂N(C-C₂N) using molecular dynamics simulations. The in-plane thermal conductivities of C₂N monolayers along zigzag and armchair directions are 73.2 and 77.3 W m⁻¹ K⁻¹, respectively, and can be effectively manipulated by point defects, chemical doping, and strain engineering. Remarkably, nitrogen vacancies have a more substantial impact on reducing the thermal conductivity than carbon vacancies because of the more pronounced suppression of the high-frequency peaks. The difference in doping sites leads to a change in phonon mode localization. When the C₂N size is small, as the tensile strain increases, k_i is affected by dimensional lengthening due to stretching in addition to tensile strain. The interlayer thermal resistance decreases with increasing layer number and interlayer coupling strength. The AA stacking gives rise to a lower thermal resistance than the AB stacking when the heat flow passes through the multilayer due to the weaker in-plane bonding strength. Moreover, various possible atomic structures of C₂N/C-C₂N in-plane heterojunctions and the effect of carbon and nitrogen vacancies on interfacial thermal conductance are explored. The results provide valuable insights into the thermal transport properties in the application of C₂N-based electronic devices.