Effect of laser annealing on gold nanofilm

Abstract

Laser annealing of gold nanofilms deposited on quartz substrate was performed. RF CO 2 laser of variable power in the range 1–20 W with beam quality of 1.1 was used to anneal gold films of 20, 40 and 60 nm thickness. AFM analysis emphasize that smaller nanocrystal sizes of 88 nm was obtained for 20 nm gold film. While optimum absorbance peak exists at about 667 nm for smaller film thickness. Thermal analysis for the annealing process was also conducted using COMSOL Multiphysics software. Optimal temperature of 938 K was achieved when 10 W laser power and 1 mm/s scanning speed were used to anneal 20 nm gold film thickness. Design of expert analysis was used for better understanding of the laser annealing gold nanofilm since convolution of many parameters are affecting the process output.