Graphene Sensor Based on Surface Plasmon Resonance for Optical Scanning

The experimental and theoretical evaluation of a simple, low cost, and compact footprint, as well as a high resolution graphene plasmonics sensor are presented here for optical scanning. The strong coupling condition between incident light and excited surface plasmon resonance (SPR) of the graphene-SiO2/Si structure is thoroughly utilized to assay the proposed model. The substrate thickness, incident angle, and coupling conditions are considered to obtain optimal results including the highest resolution, and physical and optical properties including graphene thickness. The results show that high-resolution condition can be provided when the chemical vapor deposition monolayer graphene thickness is 0.335 nm, SiO2/Si thickness is 300 nm, and incident angle is theta = 62.5 degrees. Moreover, atomic force microscopy (AFM) and scanning electron microscopy (SEM) are employed to obtain and investigate the physical structures. Finally, it is shown that the highest sensitivity can be achieved by a strong coupling condition.