Hierarchical nano/micro moth eye-like polymer film using solid/liquid interfacial reaction at room temperature.

A simple pathway for the fabrication of real moth eye-like patterned (MEP) polymer film with a double layered nano/micro hierarchical structure is demonstrated through a solid/liquid interfacial reaction at atmospheric conditions. A convex-structured polyvinyl alcohol (PVA) film including CdCl2 was first fabricated using a self-organized honeycomb-patterned porous film as a template. The CdCl2/PVA convex film was immersed into Na2S/ethanol solution to facilitate the reaction between CdCl2 and Na2S at the solid/liquid interface, led to the functionalization of CdS nanoparticles to the convex structured PVA film. The tunable introduction of interfacial reaction resulted in the formation of CdS moth eye-like nanoarray on the top-surface of PVA convex microarray, which mimicked the real moth eye (PVA-CdS MEP). PVA-CdS MEP film with a double moth eye-like structure showed the improved antireflective property in comparison with flat and convex structured PVA films. The PVA-CdS MEP film showed the photo-response under simulated solar light radiation and flexible duration after 500 cycles of folding.