Nanolaminate-based antireflection coatings for enhanced scratch and tribological performance

Developing durable antireflection (AR) coatings with sapphire-like hardness and high transparency faces a significant challenge. Conventionally, achieving these requirements involves depositing thick, high-hardness nitride films. Here, we proposed an alternative approach that combines nanolaminate materials with optical design, overcoming the brittleness of thick nitride films. We selected Ta₂O₅/Si₃N₄ nanolaminates with similar refractive indices, improving tribological and optical performance through a unique optomechanical method. Our proposed AR coating exhibited a low reflectance of 0.8% (420-780 nm) and remarkable hardness of 22.8 GPa, and demonstrated the ability to withstand abrasion from steel wool up to 3,000 times on a glass substrate. This work successfully achieves a balance between hardness and toughness, opening new avenues for the development of highly durable coatings.