Preparation and Characterization of Silver Substrates Coated with Antimony-Doped SnO2 Thin Films for Surface Plasmon Resonance Studies

This paper reports on the preparation of silver/antimony-doped tin oxide (Ag/SnO2:Sb) hybrid interfaces using magnetron sputtering and their characterization. The influence of the Sn target composition (doping with 2 or 5% Sb) on the electrochemical and electrical characteristics of the hybrid interface was investigated using X-ray photoelectron spectroscopy (XPS), sheet resistance measurements, cyclic voltammetry, scanning tunneling microscopy (STM) and surface plasmon resonance (SPR). The best interface in terms of electrical conductivity and SPR signal is a hybrid interface with a 8.5 ± 0.3 nm thick SnO2:Sb layer obtained from a Sn target with 2% Sb deposited on 38 nm thick silver film. Different strategies to link functional groups onto the Ag/SnO2:Sb interface are also presented.