Plasmonic improvement photoresponse of vertical-MoS2 nanostructure photodetector by Au nanoparticles

Vertically aligned MoS₂ nanosheets have attracted considerable attention due to their large specific surface area and extensively exposed edges, useful for application in optoelectronic devices. Here, a photodetector based on vertical MoS₂ (V-MoS₂) nanosheets grown by chemical vapor deposition techniqueon a pre-patterned SiO₂ substrate is demonstrated. The nanosheets are well [002] oriented, with high crystalline quality and have an estimated thickness of 10–50 nm. We show a significant photocurrent enhancement through plasmonic effect mediated by Au nanoparticle (NP) decorated at the surface of the photodetector. The photocurrent of the photodetector decorated with Au NPs increased by 20 and 2.1 times in comparison with the dark current and the sample without Au NPs, respectively. These enhancements can be induced by the localized surface plasmonic resonance, effective charge transfer or increasing in light scattering. The combination of V-MoS₂ and Au NPs treatment enables the functionalization of bulk MoS₂ for optoelectronic applications.