Localized Surface Plasmon Induced Position-Sensitive Photodetection in Silicon-Nanowire-Modified Ag/Si

Area of Science:

• Materials Science
• Nanotechnology
• Optoelectronics

Background:

• Surface plasmon resonance is crucial for enhancing photoelectric device efficiency.
• Metallodielectric nanostructures are key to boosting light absorption and charge generation.
• Silicon nanowires (SiNWs) offer unique properties for nanostructure modification.

Purpose of the Study:

• To investigate the impact of silicon nanowires on metal-semiconductor structures for photoelectric applications.
• To explore the enhancement of the lateral photovoltaic effect (LPE) using Ag/SiNWs/Si nanostructures.
• To elucidate the role of localized surface plasmons (LSPs) in improving photodetector sensitivity.

Main Methods:

• Fabrication of Ag/SiNWs/Si metal-semiconductor structures.
• Measurement of the lateral photovoltaic effect (LPE) and positional sensitivity.
• Utilizing surface-enhanced Raman scattering (SERS) with rhodamine-6G.
• Performing finite-difference time-domain (FDTD) simulations.

Main Results:

• The Ag/SiNWs/Si system exhibited a significantly increased LPE, reaching a maximum positional sensitivity of 65.35 mV mm^-1.
• This sensitivity represents a ≈53-fold and ≈1000-fold improvement over conventional Ag/Si and SiNWs/Si structures, respectively.
• Silver-coated SiNWs were shown to strongly support localized surface plasmons (LSPs), confirmed by SERS and FDTD simulations.

Conclusions:

• Localized surface plasmons (LSPs) are a primary mechanism for the observed enhancement in the lateral photovoltaic effect.
• The developed Ag/SiNWs/Si nanostructure provides an effective strategy for enhancing photoelectric conversion efficiency.
• This approach offers a promising route to significantly improve the sensitivity of photodetectors.