Understanding the mechanical and thermodynamic properties of transition-metal dichalcogenides (TMDs) and their heterostructures is pivotal for advancing the development of flexible semiconductor devices, and molecular dynamics (MD) simulation is widely applied to study these properties. However, current uncertainties persist regarding the efficacy of empirical potentials in MD simulations to accurately describe the intricate performance of complex interfaces within heterostructures. This study addresses these challenges by developing an interatomic potential based on deep neural networks and first-principles calculations. Specifically focusing on MoS2/WS2 heterostructures, our approach aims to predict Young's modulus and thermal conductivities. The potential's effectiveness is demonstrated through the validation of structural features, mechanical properties, and thermodynamic characteristics, revealing close alignment with values derived from first-principles calculations. A noteworthy finding is the substantial influence of the load direction on Young's modulus of heterostructures. Furthermore, our results highlight that the interfacial thermal conductance of the MoS2/WS2 heterostructures is considerably larger than that of graphene-based interfaces. The potential developed in this work facilitates large-scale material simulations, bridging the gap with first-principles calculations. Notably, it outperforms empirical potentials under interface conditions, establishing its significant competitiveness in simulation computations. Our approach not only contributes to a deeper understanding of TMDs and heterostructures but also presents a robust tool for the simulation of their mechanical and thermal behaviors, paving the way for advancements in flexible semiconductor device manufacturing.

Two-dimensional gallium nitride (2D-GaN) has great potential in power electronics and optoelectronics. Heat dissipation is a critical issue for these applications of 2D-GaN. Previous studies have shown that higher-order phonon–phonon scattering has extremely strong effects on the lattice thermal conductivity (κlat) of 2D-GaN, with the fourth-order interatomic force constants (4th-IFCs) calculated using experienced atomic displacement in the finite difference method. In this work, it is found that the 4th-IFCs of 2D-GaN are quite sensitive to atomic displacement in the finite difference method. The effects of the four-phonon scattering can be severely overestimated with non-convergent 4th-IFCs. The κlat from three-phonon scattering is reduced by 65.6% due to four-phonon scattering. The reflection symmetry allows significantly more four-phonon processes than three-phonon processes. It was previously thought the electron–phonon interactions have significant effects on the κlat of two-dimensional materials. However, the effects of electron–phonon interactions on the κlat of both n-type and p-type 2D-GaN at high charge carrier concentrations can be neglected due to the few phonon–electron scattering channels and the relatively strong four-phonon scattering.