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

Abstract

Surface plasmon-based approaches are widely applied to improve the efficiency of photoelectric devices such as photosensors and photocells. In order to promote the light absorption and electron-hole pair generation in devices, metallodielectric nanostructures are used to boost the growth of surface plasmons. Here, silicon nanowires (SiNWs) are used to modify a metal-semiconductor structure; thus, Ag/SiNWs/Si is manufactured. In this system, a large increased lateral photovoltaic effect (LPE) is detected with a maximum positional sensitivity of 65.35 mV mm , which is ≈53-fold and 1000-fold compared to the conventional Ag/Si (1.24 mV mm ) and SiNWs/Si (0.06 mV mm ), respectively. It is demonstrated that localized surface plasmons (LSPs) contribute a lot to the increment of LPE. Furthermore, through the surface-enhanced Raman scattering spectra of rhodamine-6G and finite-difference time-domain simulation, it is illustrated that silver-coated SiNWs support strong LSPs. The results propose an enhancement mechanism based on LSPs to facilitate the photoelectric conversion in LPE and offer an effective way to improve the sensitivity of photodetectors.

Lateral Photovoltaic Effect and Photo‐Induced Resistance Effect in Nanoscale Metal‐Semiconductor Systems

“…Such LSP induced photoelectric enhancement is also found in the mentioned SiNWs modified Ag/Si structures . Likewise, in this system, strong LSPs are induced by silver nanostructure modified SiNW arrays.…”

“…Mei et al. have demonstrated a huge enhancement of photoelectric performance in silicon‐nanowire‐modified Ag/Si structure, where the silicon nanowires (SiNWs) were fabricated by metal‐assisted chemical etching (MACE) . Figure a–c shows the surface morphologies (Top view of SEM images) of SiNWs, SiNWs with silver nanoparticles, and Silver nanoparticles on Si substrate.…”

Broadband Photodetectors Enabled by Localized Surface Plasmonic Resonance in Doped Iron Pyrite Nanocrystals

“…In conventional semiconductors, the spectral range of the photoresponse is limited to the photons of energies above the energy bandgap of the semiconductor . One approach to break this fundamental limit is combining plasmonic metallic particles or films with localized surface plasmon resonances (LSPRs) . Another one is doping into the semiconductor nanocrystals to induce strong LSPRs .…”

Ultra‐High and Fast Ultraviolet Response Photodetectors Based on Lateral Porous GaN/Ag Nanowires Composite Nanostructure

“…Using plasmonic is an effective approach to simultaneously realize high sensitivity and fast speed of photodetectors due to strong light trapping and efficient carriers' transport process at the metal/semiconductor interfaces induced by localized surface plasmon resonance (LSPR) effect 11,24–27. However, since mostly reported metal nanostructures are usually distributed at the semiconductor surface, the effective light absorption region is confined to the surface within a few hundred nanometers, which limits the overall UV photoresponse of the semiconductors to only ≈10 A W −1 25,28–30.…”