Morphological and SERS Properties of Silver Nanorod Array Films Fabricated by Oblique Thermal Evaporation at Various Substrate Temperatures

Abstract

Aligned silver nanorod (AgNR) array films were fabricated by oblique thermal evaporation. The substrate temperature during evaporation was varied from 10 to 100 degrees C using a home-built water cooling system. Deposition angle and substrate temperature were found to be the most important parameters for the morphology of fabricated films. Especially, it was found that there exists a critical temperature at similar to 90 degrees C for the formation of the AgNR array. The highest enhancement factor of the surface-enhanced Raman scattering (SERS), observed in the Ag films coated with benzenethiol monolayer, was similar to 6 x 10(7). Hot spots, excited in narrow gaps between nanorods, were attributed to the huge enhancement factor by our finite-difference time-domain (FDTD) simulation reflecting the real morphology.