Ultra-sensitive and selective 2D hybrid highly doped semiconductor-graphene biosensor based on SPR and SEIRA effects in the wide range of infrared spectral

Abstract

Simultaneous amplification of surface plasmon resonance (SPR) and surface enhanced infrared absorption (SEIRA) spectroscopy can be very effective for the operation of biosensors in a wide range of mid-IR to terahertz wavelengths, with considering the position of the vibrational spectrum and the intensity of the absorption band to detect small biomolecules. In this paper, we introduce the hybrid high doped semiconductor-graphene plasmonic biosensor to achieve this goal. Our proposed structure has been formed of high doping InAsSb nanoribbons beside the plates or nanoribbons of graphene. By changing the geometrical characteristics of the proposed structure and selecting the appropriate fermi level for graphene nanostructures, the high doped semiconductor-graphene biosensor has been able to increase the sensitivity of all-semiconductor biosensors in the presence of small amounts of biomolecules to 156%. While its quality and Figure of merit (FOM) has also been greatly improved. The introduced type of biosensors, by combining the benefits of all-graphene and all-semiconductor biosensors and by controlling the fermi energy level of graphene and selecting the appropriate doping level for semiconductor can be the beginning for highly sensitive tunable biosensors over a wide range of wavelengths to identify fingerprints of specific biomolecules.