Preparation of “Black” Ag-Mo Alloy Films with Strong Light-Trapping Properties

Black Ag-Mo granular films were formed spontaneously on silver (Ag) sheets/targets by composite target sputtering. The morphology, composition, phase, crystal structure and reflectivity of black Ag-Mo films were characterized by SEM, EDS, XRD, TEM and UV spectrophotometer. Results show that Ag-Mo alloy films with conical particle arrays are spontaneously formed on sputtered Ag sheets, and the Ag-Mo granular films exhibit strong light trapping effect in the visible wavelength range, resulting in black appearance of Ag sheets. The strong light-trapping properties can be ascribed to the conical particle arrays closely arranged on the Ag-Mo films, which caused the reflectivity of the Ag sheets to reduce substantially from 90 % down to 10 %. The Ag-Mo granular films prepared by magnetron sputtering methods provide a new idea for fabrication of high light trapping materials.