Low power laser directed deposition of silver thin films

Abstract

Polycrystalline metalic thin films are widely used in many applications such as magnetic storage media, in micro-nano-electronic devices and as protective or decorative coatings. Silver thin films, specifically, are also indispensable for optical applications, due to their high reflectance over a wide spectral range and are able to support a propagating surface Plasmon polariton (SPP) in an attenuated total reflection (ATR) sensor as well. In this report, the novel method for the deposition of silver thin films through the illumination of low power laser in a solution containing citrate and silver ions will be carefully described. With this method silver can be deposited on a numerous of substrates such as metals, semiconductor, polymers or even composites. In this report, the effects of applied light dosage (energy), chemical concentration and wavelength of lasers on the thin film deposits were investigated to support a proposed novel mechanism on the nucleation and growth of such Ag films and to outline the different conditions under which surface nucleation will be favored. Lastly, to provide guidance to future operational control, an empirical modeling for this novel mechanism is also proposed.