Enhanced radiative emission from monolayer MoS2 films using a single plasmonic dimer nanoantenna

Abstract

By thinning transition metal dichalcogenides (TMDCs) to monolayer form, a direct bandgap semiconductor emerges which opens up opportunities for use in optoelectronic devices. However, absorption and radiative emission is drastically reduced which hinders their applicability for practical devices. One way to address this challenge is to design plasmonic resonators that localize electric fields within or near the two-dimensional (2D) material to confine excitation fields and increase Purcell factors. Previous studies have successfully utilized this method for enhancing radiative emission in 2D-TMDCs by using large area plasmonic arrays that exhibit complex plasmonic interactions due to near and far-field couplings that take place over many periods. In this study, we demonstrate the photoluminescence enhancements in monolayer MoS2 under single Au nanoantennas which only exhibit near-field interactions. Here, the enhancements originate from excitation of near-field plasmons confined within 20 nm of monolayer MoS2 which yields a peak photoluminescence enhancement of 8-fold and an area corrected photoluminescence enhancement >980 fold. Additionally, simulated enhancement trends are found to agree well with experimental results to understand the optimal design requirements. Our results will provide a better understanding of local emission enhancements in 2D materials over small areas of MoS2 that are essential for future applications of truly compact optoelectronic devices based on two-dimensional or reduced dimensionality materials.

Emerging photoluminescence from defective vanadium diselenide nanosheets

“…Several different strategies have also been employed to intensify and tune the photoluminescence (PL) from 2D TMDs. Chemical treatments [29][30][31], alloying [32][33][34][35], coupling with surface plasmon polaritons [36,37], integration with photonic crystal cavities [38,39], and strain engineering [40] are some of these proposed methodologies to improve the band-to-band PL characteristics of 2D TMDs. Moreover, it is found that a strong sub-band-gap PL can be originated from defect-mediated transitions [23,25,[41][42][43][44][45][46] that are of great interest in the design of NIR LEDs.…”

Polarized resonant emission of monolayer WS2 coupled with plasmonic sawtooth nanoslit array

“…Additionally, the highly efficient growth by chemical vapor deposition (CVD) is promising to meet the demand of mass production 11 . Benefiting from these advantages, TMDCs offer a unique platform for investigation of intriguing light-matter interactions at the nanoscale through, besides the well-known van der Waals heterostructures 12,13 , the integration with artificial materials, such as photonic nanocavities 14,15 , plasmonic nanostructures 16 , and single nanoparticle antennas 17 . This enables the establishment of compact optoelectronic devices, including tunable light emitters 18 , nanolasers 19,20 , electro-optic modulator 21 , optical switches 22 , biosensors/detectors 23,24 , fieldeffect transistors 25 , quantum devices 26 , etc., which are the key elements of the next-generation integrated photonic circuits.…”

Strong Interference in Planar, Multilayer Perfect Absorbers: Achieving High-Operational Performances in Visible and Near-Infrared Regimes

“…It is, therefore, essential to couple these 2D planes with light-trapping schemes that obtain broad and strong light absorption. As stated previously, strong, near-field coupling using plasmonic nanounits is one of these solutions [54], [55]; however, this article aims to summarize the planar multilayer trapping strategies. The proper architecture for light absorption in these 2D semiconductors is to couple them into 1D photonic crystals (PCs).…”