Photo-Induced Self-Assembly of Silver Nanoparticles for Rapid Generation of First and Second Surface Mirrors

Interesting mirror-like, highly reflective, and conductive silver films have been successfully generated directly on a glass slide using a simple and fast photoinduced approach. A water-based photosensitive formulation containing the silver precursor and a photogenerator of free radicals was used. It was applied like paint and exposed to UV light for a few seconds, in the absence of any additional reducing agents and without further treatment of any kind. This approach allowed ultrathin films of silver nanoparticles to be generated in situ (AgNPs) on the back side of the glass substrate. The particles are homogeneously autoassembled onto the glass surface and the glass/silver diopter exhibits a high reflective character. With such an experimental arrangement, reflective surfaces are obtained: in contact with the glass slide, which is called the second surface mirror, and on the air side, which is called the first surface mirror. Quite interestingly, these reflective and conductive thin films exhibit strong natural adhesion on the glass substrate without the need for enhancing treatments (sensitization or activation) to improve the adhesion of the silver layer to the glass, as usual with silver glass mirrors. The influence of several chemical and photonic parameters has been examined in order to optimize the final optical and electrical properties of these silver films.