Enhanced mechanical and thermal properties of two-dimensional SiC and GeC with temperature and size dependence

摘要

Two-dimensional materials with novel mechanical and thermal properties are available for sensors,photodetectors,thermoelectric,crystal diode and flexible nanodevices.In this investigation,the mechanical and thermal properties of pristine SiC and GeC are explored by molecular dynamics simulations.First,the fracture strength and fracture strain behaviors are addressed in the zigzag and armchair directions at 300 K.The excellent toughness of SiC and GeC is demonstrated by the maximal fracture strain of 0.43 and 0.47 in the zigzag direction,respectively.The temperature-tunable tensile strength of SiC and GeC is also investigated.Then,using non-equilibrium molecular dynamics(NEMD)calculations,the thermal performances of SiC and GeC are explored.In particular,the thermal conductivity of SiC and GeC shows a pronounced size dependence and reaches up to 85.67 W·m^(-1)-K^(-1)and 34.37 W·m^(-1)-K^(-1),respectively.The goal of our work is to provide a theoretical framework that can be used in the near future.This will enable us to design an efficient thermal management scheme for two-dimensional materials in electronics and optoelectronics.