Comparative study of atomic models of plastic deformation mechanism in ductile inorganic semiconductors: A theoretical discussion

Recently developed ductile inorganic semiconductors have opened a new avenue toward potential applications such as flexible electronics. Significant studies have been conducted based on different atomic models to understand the deformation mechanism using first-principle calculations; however, the comparative study on these atomic models remains unexplored. In this paper, taking Ag2S as an example, we simulated the slipping process using bulk, slab, and tilt-cell models. Systematic supercell tests were performed to investigate the convergence of the slip/cleavage energy based on the three atomic models. It was found that a reasonably large supercell is required to converge the slip/cleavage energy, and the ratio between minimum cleavage and maximum slip energy converges to a comparable value among different atomic models, where the tilt-cell and slab models show slightly higher energy ratio values compared with the bulk model. However, the comparison of different exchange-correlation functionals and van der Waals corrections indicates that the calculations of slip and cleavage energies are sensitive to the choice of calculation methods, highlighting the importance of using the same method for comparing slip and cleavage energies of different materials. This work provides insights into understanding different atomic models of ductility mechanisms in ductile inorganic semiconductors.