Laser damage depths, carbon film thickness and possible zero metal enhancement in silver/pyridine sers

Abstract

Surface-enhanced Raman scattering (SERS) by pyridine on anodized silver electrodes emanates from faint but visible carbon-overlayered regions within the laser damage microzone. Scanning electron microscopy reveals that initial silver surface damage consists of a central zone (0.03 mm diameter) of increased roughness surrounded by a halo (0.06 nm diameter) of intermediate roughness. Laser perforation studies on thin (500 nm) film electrodes reveal that the depth of laser damage under typical SERS conditions is ≈1250 silver-atom layers. Optical skin-depth measurements and surface tone comparisons indicate a carbon film depth of ≈300 layers. The implications for possible zero metal enhancement are considered. Show more