Sensing Performance Study of SiC, a Wide Bandgap Semiconductor Material Platform for Surface Plasmon Resonance Sensor

Abstract

The sensing properties of a surface plasmon resonance (SPR) based waveguide sensor on a wide bandgap semiconductor, silicon carbide (SiC), were studied. Compared to other waveguide sensors, the large bandgap energy of SiC material allows the sensor to operate in the visible and near infrared wavelength range, while the SPR effect by a thin gold film is expected to improve the sensitivity. The confinement factor of the sensor at various wavelengths of the incident light and refractive index of the analyte were investigated using an effective index method. Since the change of analyte type and concentration is reflected by the change of refractive index, the sensing performance can be evaluated by the shift of resonant wavelength from the confinement factor spectrum at different refractive index. The results show that the shift of resonant wavelength demonstrates linear characteristics. A sensitivity of 1928 nm/RIU (refractive index unit) shift could be obtained from the refractive index of 1.338~1.348 which attracts research interests because most biological analytes are in this range.