MXene-GST-Graphene-Si Composited Tunable Surface Plasmon Resonance-Based Refractive Index Sensor Operated at Infrared Optical Wavelength

We proposed the numerical study and analysis of a tunable surface plasmon resonance-based refractive index sensor for the infrared frequency spectrum. The proposed structure was formed using Au-Si-Graphene-GeSbTe(GST)-MXene-BK7 composited material structure. The proposed design has been numerically simulated over the infrared wavelength of $1.3\ \mu \mathrm{m}$ to $2.5\ \mu \mathrm{m}$. This structure can be tunable with different temperature values because of the state of the phase material GST. The GST material provides two forms of tunability: amorphous state (aGST) and crystalline state (cGST). This design is numerically investigated over the optical refractive index of 1 to 2.4, covering the standard refractive index of biomarker concentrations such as haemoglobin, urine, cortisol, cancerous etc. The proposed structure's tunable behaviour will help design a biosensor structure and its point of care device for a wide range of biosensing or refractive index sensing applications.