Investigation of graphene coating effects on the tribological properties of polycrystalline gallium arsenide during nanoscratching

Abstract

Polycrystalline gallium arsenide (poly-GaAs) is a crucial material for optoelectronic and high-speed electronic devices. Its importance in semiconductor applications, including those in solar cells, lasers, and microwave-integrated circuits, is increasing. A comprehensive understanding of material removal mechanisms during scratching is crucial for optimizing the design and performance of poly-GaAs-based nanodevices. In this study, we used molecular dynamics simulations to construct a model of a poly-GaAs substrate coated with a graphene layer. Subsequently, diamond-tip scratching experiments were performed on the model at a constant speed. Experimental results demonstrate that the graphene layer considerably improves the wear resistance and hardness of the substrate, effectively reducing surface wear, potential energy accumulation, and subsurface damage. However, as the scratching depth increases, the scratching force, subsurface damage depth, friction coefficient, and surface wear of the substrate also increase. Additionally, the incorporation of a graphene layer effectively improves the load-bearing capacity of the substrate during fully elastic deformation, demonstrating excellent superlubrication performance across a broad range of operating conditions. These findings offer valuable insights into the design of poly-GaAs-based nanodevices and highlight the potential of graphene for protection and lubrication applications.