Sensitivity Enhancement of 2D Material-Based Surface Plasmon Resonance Sensor with an Al-Ni Bimetallic Structure

In this paper, a variety of 2D materials on the surface plasmon resonance sensor based on Al-Ni bimetallic layer are compared. Simulation results indicate that lateral position shift, which is calculated according to the real and imaginary parts of the refractive index of material, can be used as an effective parameter to optimize the sensitivity. By using the parameters for optimizing the SPR structures, the results show that the multiple layer models of Al(40 nm)-Ni(22 nm)-black phosphorus (BP)(1 L) and Al(40 nm)-Ni(22 nm)-blue phosphorus (BlueP)/WS₂(1 L) exhibit average angular sensitivities of 507.0 °/RIU and 466 °/RIU in the refractive index range of 1.330-1.335, and maximum sensitivity of 542 °/RIU and 489 °/RIU at the refractive index of 1.333, respectively. We expect more applications can be explored based on the highly sensitive SPR sensor in different fields of optical sensing.