Impact of Nanograting Phase-Shift on Light Absorption Enhancement in Plasmonics-Based Metal-Semiconductor-Metal Photodetectors

Figure 4

Schematic diagrams of different Au nanogratings (a) without the phase shift and (b) with the phase shift, 𝛿≡2𝜋𝑥_𝑔𝑝/Λ. (c) General trapezoidal-shaped nanograting profile, with the aspect ratio defined as the trapezoid top-to-bottom base ratio.

(a)

(b)

(c)