FDTD simulation of Kretschmann based Cr-Ag-ITO SPR for refractive index sensor

In this paper, a Kretschmann based surface plasmon resonance sensor using silver (Ag) and indium tin oxide (ITO) on chromium (Cr)-coated BK7 substrate has been analyzed for refractive index sensor. By numerical simulations, the thickness of the ITO layer along with Ag thin film have been optimized to achieve the best performance of the sensor in terms of sensitivity and Figure of Merit (FOM). The best sensor performance was achieved by Cr(0.5 nm)/Ag(30 nm) with sensitivity value of 69.88 degrees/RIU and FOM of 15.19 whereas Cr(0.5 nm)/Ag(30 nm)/ITO(10nm) gave sensitivity and FOM of 68.77 degrees/RIU and 11.26, respectively. The deposition of Cr enhanced the attachment of Ag layer to prism whereas incorporating ITO on Cr/Ag sensor interface helps to protect the Ag layer from oxidation and preserve its sharp optical signal. Hence, this Ag based SPR interface with ITO coated can be useful for sensing refractive index changes for analyte detection. (C) 2018 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the Nanotech Malaysia 2018.