Figure 5
Fabrication results and performance comparison of photodetectors with film, cone-shaped, and funnel-shaped structures. (a) Schematic of the photodetector device and cross-sectional SEM images of film, cone-shaped, and funnel-shaped structures fabricated on silicon-on-insulator (SOI) substrate-based photodetectors (scale bars: 5 µm). Insets are enlarged SEM images of the surface structures on the photodetectors (scale bars: 500 nm). (b) Photocurrent density of photodetectors with film, cone-shaped, and funnel-shaped structures when exposed to a halogen lamp at 550 nm wavelength with an intensity of 0.65 mW/cm2 and under an applied voltage of 0.1 V. (c) Current response in the photodetector with funnel-shaped structures when illuminated with a halogen lamp of varying intensities. (d) Photocurrent density of the photodetector with funnel-shaped structures in response to varying light intensities. (e) Measured photocurrent densities for with film, cone-shaped, and funnel-shaped structures. (f) Responsivity of photodetectors with film, cone-shaped, and funnel-shaped structures across the 400–1000 nm wavelength range.
