Influence of Annealing on the Optical Properties of Vacuum Deposited Silver Thin Films

Thin Silver films of thickness 15nm were prepared by thermal evaporation on well cleaned glass substrates at room temperature at a pressure of 2x10(-5) mbar with the deposition rate of 0.01A/sec and annealed in air for an hour at temperatures between 300 degrees cand400 degrees c. The prepared films were characterized by X-ray diffraction (XRD), UV-visible spectroscopy and AFM. The mean grain size of the film at different annealing temperatures was determined by the X-ray diffraction pattern by using Scheer's formula. It is found that from absorbance studies surface Plasmon peak position decreases as the annealing temperature increases and blue shifted. And also from transmittance studies the thermal effect of silver film strongly affects the optical transmittance. From AFM studies the average particle size and RMS surface roughness increase with increase of annealing temperatures..