Theoretical Study of the Doping Effects of n-type and p-type Silicon on the Surface Plasmon Resonance Using a 2D Grating

Abstract

A theoretical study on the excitation of surface plasmon (SP) through a 2D doping silicon gratingis present. Both n- and p-type doping silicon were used. The doping effects of n -type and p-type on surface plasmon resonance (SPR) were calculated and discussed in detail, using a rigorous coupled-wave analysis (RCWA) as a numerical method. It was observed that the doping effects of both n-type and p-type silicon were almost the same. The majority of charge carriers N in silicon play an important role in the sensitivity of surface plasmon resonance. From the numerical analysis, the doped silicon behaves as a dielectric for low charge carriers (N = 3.1019 cm− 3), whereas for high charge carriers (2.1020 cm− 3 ≤ N), silicon become conductive as a metal. This suggests that the effect of the high charge carriers on SPR is more remarkable than that of the low charge carriers. Furthermore, the effects of grating structural parameters such as grating depth and grating period on the full width at half-minimum of SPR, minimum reflectance at resonance, and resonance anglewere investigated. It was found that the SPR curves were very sensitive to these parameters. Hence, it was concluded that a 5.1020 cm− 3 of charge carriers, a 6 μ m of grating period and a 0.6 μ m of grating depth were important for a higher excitation of surface plasmon.