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

Abstract

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 the SiC and GeC is obtained by the maximal fracture strain as 0.43 and 0.47 in the zigzag direction, respectively. Interestingly, the temperature-tunable tensile strength of the SiC and GeC is also investigated. Then, using non-equilibrium molecular dynamics (NEMD) calculations, the thermal performances of the SiC and GeC are explored. In particular, the thermal conductivity of the SiC and GeC present a pronounced size-dependent thermal conductivity, which can be enhanced up to 85.67 Wm–1K–1 and 34.37 Wm–1K–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 2D materials in electronics and optoelectronics.

Tunable Thermal Conductivity of Two-Dimensional SiC Nanosheets by Grain Boundaries: Implications for the Thermo-Mechanical Sensor

“…Obviously, the GBs can suppress the thermal conductivity of the pure SiC monolayer because the GBs can result in significant phonon scattering. 51 As shown in Figure 2b, an increase in the GBs angle leads to a more pronounced formation of pentagonheptagon defects, which is demonstrated in Figure S1 in the Supporting Information, further substantializing the reduction in the thermal conductivity of SiC GBs. Furthermore, the atomic heat flux vectors at angles of 5.09, 21.78, and 42.1°are calculated using J i = e i v i − S i v i , where e i , v i , and S i are atomic energy, the velocity vector consisting of v x , v y , and v z ; and the stress tensor consisting of S x , S y , S z , S xy , S xz , and S yz , respectively.…”

“…In our previous study, 51 we also explored the thermal properties of SiC monolayers using the NEMD method and such as Tersoff potential. The results were found to be consistent with the reported investigation, 52 suggesting the accuracy of the results of this work.…”

Understanding the influence of secondary building units on the thermal conductivity of metal–organic frameworks via high-throughput computational screening

“…In our study, LAMMPS 34–36 was employed to conduct equilibrium molecular dynamics (EMD) simulations 37 for the thermal conductivity of MOFs through the corrected heat flow calculation method, 38 which includes contributions from many-body potentials. The thermal conductivity was calculated using the equilibrium molecular dynamics simulations and the Green–Kubo formulation, 39 which is based on the fluctuation-dissipation theorem.…”

Type-II 2D AgBr/SiH van der Waals heterostructures with tunable band edge positions and enhanced optical absorption coefficients for photocatalytic water splitting

“…11 The revelation of graphene in 2004 marked a signicant turning point in materials research, 12 instigating a substantial fascination with 2D materials. [13][14][15][16][17][18] These materials offer numerous benets over traditional materials, such as a modiable bandgap, 19,20 a con-siderable specic surface area, 21 and distinctive photoelectric properties that conventional materials lack. 22,23 These remark-able pro-perties have opened up a new prospect for exploring photocatalysts.…”