Design of fracture-resistant silicon structure with molecular dynamics simulation

Abstract

The inherent brittleness of crystalline silicon is a cause of concern for processing, handling and application of the material. Here a simulation-based design is proposed to reduce the risk of catastrophic brittle fracture of devices and components made of silicon. In this scheme, ultrathin layers of amorphous silicon are introduced within the crystalline silicon to create a multilayered laminated structure. Using molecular dynamics simulations, we demonstrate that in this nanolaminate, a crack growing within the crystalline region gets pinned at the amorphous layers. This phenomenon occurs due to the observed ductility in amorphous silicon, which resembles the shear-band mediated deformation of metallic glasses. Asa consequence, the catastrophic failure is averted by localizing the damage and preventing it from extending across the material.