Graphene/WS₂ Nanodisk Van der Waals Heterostructures on Plasmonic Ag Nanoparticle-Embedded Silica Metafilms for High-Performance Photodetectors

Abstract

Coupling plasmons and excitons provide a promising approach to enhance the performance of photodetectors based on two-dimensional (2D) atomic layer heterostructures. Herein, we report a nanohybrid photodetector achieved by transferring a nonmetallic plasmonic WS2 nanodisk/graphene van der Waal (vdW) heterostructure grown using chemical vapor deposition, on metallic plasmonic Ag nanoparticles embedded in 20 nm thick silica (AgNP-metafilm) fabricated using in situ Ag and Si evaporation through a shadow mask. This nanohybrid photodetector enables not only superposition of the plasmonic effects from the two plasmonic nanostructures, but also the effective coupling of the plasmons and excitons in WS2 nanodisks upon illumination. This leads to a high responsivity of 11.7 A/W on the graphene/WS2 nanodisks/AgNP-metafilm under an incident illumination power of 5.5 × 10–8 W at 450 nm, which represents a 500% enhancement over that of the counterpart without the AgNP-metafilm. The finite element time-domain simulation of the local light field distribution indicates that the enhancement can be attributed to enhancement of exciton (electron–hole pair) excitation and exciton–plasmon coupling in the graphene/WS2 nanodisks/AgNP-metafilm photodetectors. In addition, the approach for fabrication of the graphene/WS2 nanodisks/AgNP-metafilm heterostructures is scalable and cost efficient and hence promising for commercial applications.

Probing the role of CNTs in Pt nanoparticle/CNT/graphene nanohybrids H2 sensors

“…The graphene was synthesized using chemical vapor deposition (CVD) on commercial copper foils (Sigma-Aldrich) at ∼1000 °C. The details of graphene growth and transfer were reported in previous works [21,22]. In the third step, the CNT film was transferred on top of graphene to form the 3D CNT/Gr nanohybrid (figure 1(b)).…”

Deep-Ultraviolet Photodetectors Based on Hexagonal Boron Nitride Nanosheets Enhanced by Localized Surface Plasmon Resonance in Al Nanoparticles

“…Alamri et al reported a 5 times increase in the responsivity of graphene/WS 2 nanodisk PDs by using a Ag metafilm under an illumination of 450 nm. 33 Moreover, a plasmonic-enhanced photoresponse was observed in a Ag-WS 2 /Si heterojunction by Patel and coauthors. 34 The above reports suggest that some studies have been carried out to investigate the effect of Au and Ag NPs on visible or IR PDs fabricated on graphene and TMDCs.…”

“…Besides these, plasmonic-enhanced heterostructures have also been reported. Alamri et al reported a 5 times increase in the responsivity of graphene/WS 2 nanodisk PDs by using a Ag metafilm under an illumination of 450 nm . Moreover, a plasmonic-enhanced photoresponse was observed in a Ag-WS 2 /Si heterojunction by Patel and coauthors .…”

Nanohybrid Photodetectors

“…Plasmonic metal nanostructures may be placed in proximity to nanohybrids photodetectors for the benefit of light trapping. [ 153 ] A recent work by Alamri et al [ 154 ] combines the plasmonic effects from TMD nanodiscs grown on graphene and Ag nanoparticles deposited using an in vacuo process to obtain an enhanced photoresponse.…”