Direct nanoimprint of chalcogenide glasses with optical functionalities via solvent-based surface softening

Chalcogenide glasses are attractive materials for optical applications. However, these applications often require patterning of the surface with functional micro-/ nanostructures. Such patterning is challenging by traditional microfabrication methods. Here, we present a new, to the best of our knowledge, approach of direct imprint via solvent-based surface softening, for the patterning of As₂Se₃ surface. Our approach is based on an elastomeric stamp soaked in an organic solvent. During the imprint, the solvent diffuses into the imprinted substrate, plasticizes its surface, and thereby allows its imprint at the temperature below its glass transition point. Thus, our approach combines the full pattern transfer with the maintenance of the shape of the imprinted substrate, which is necessary for optical devices. By using this approach, we demonstrated functional antireflective microstructures directly imprinted on As₂Se₃ surface. Furthermore, we showed that our approach can produce imprinted features sized down to 20 nm scale. We believe that our new approach paves the way for more future applications of chalcogenide glasses.