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[Supplmentary_Materials_doi_10.1515_nanoph-2023-0672.pdf](https://mdr.nims.go.jp/filesets/57dfb56e-4e49-4828-8701-a57fcdc137af/download)

## Creator

[Masanobu Iwanaga](https://orcid.org/0000-0002-8930-6940), [Xu Yang](https://orcid.org/0000-0001-8195-5850), [Vasilios Karanikolas](https://orcid.org/0000-0002-4829-8921), [Takashi Kuroda](https://orcid.org/0000-0001-6445-7673), [Yoshiki Sakuma](https://orcid.org/0000-0001-6804-7217)

## Rights

[Creative Commons BY Attribution 4.0 International](https://creativecommons.org/licenses/by/4.0/)

## Other metadata

[Prominently enhanced luminescence from a continuous monolayer of transition metal dichalcogenide on all-dielectric metasurfaces](https://mdr.nims.go.jp/datasets/7eb9b14c-cd55-4378-86b4-500549568ef1)

## Fulltext

Supplementary Material:Prominently enhanced luminescence from acontinuous monolayer of transition metaldichalcogenide on all-dielectric metasurfacesMasanobu Iwanaga,∗,† Xu Yang,†,‡ Vasilios Karanikolas,†,¶ Takashi Kuroda,†and Yoshiki Sakuma††National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba 305-0044, Japan‡Present address: Institute of Materials and Systems for Sustainability, Nagoya University,Nagoya 464-8601, Japan¶Present address: Materials Modelling, Institute of Materials Science, Technical University ofDarmstadt, 64287 Darmstadt, GermanyE-mail: iwanaga.masanobu@nims.go.jpS1. Resonant Electromagnetic FieldsFigure S1 shows a set of electric- and magnetic-field intensity distributions in left and right panels,respectively, under the excitation condition at the reflectance peak E in Figure 2A. Scale bars indi-cate the intensities under condition that the incident intensity is set to unity. In both components,more than 100-fold field enhancement is observed. The magnetic field distribution, |H|2, exhibitsa distribution quite similar to Figure 2D, strongly suggesting that the resonant mode is essentiallythe same to that appears in Figure 2D. The electric field distribution, |E|2, also shows a ditributionS-1qualitatively similar to Figure 2D.C:¥ActiveMine¥F90¥CyberSC¥AOBA¥SOI-MSFs¥EM-fields_SOI-MSF_a400d228_since20230513.pxp  230526a_e1Originally, Figure 2E. Transferred to here in the revision on 10 Nov 2023 for Nanophotonics.|H|2, xz0 148.80 112.4|E|2, xzFigure S1: Electromagnetic field intensity distributions at the reflectance peak E in Figure 2A.S2. Basic Properties of WS2 Atomic LayerFigure S2 shows optical properties of an as-grown WS2 atomic layer in this study. They were mea-sured at room temperature. Figure S2A presents Raman scattering spectrum with WS2-mode indi-cations of E12g and A1g and MoS2-mode red arrows. Thus, the atomic layer is, strictly, WxMo1−xS2.The ratio x is estimate to be x ≥ 0.9 or less from the comparison with literature,S1 indicating thatW is dominant. Therefore, in Figure S2, we call the TMDC WS2 for simplicity.Raman and PL of as-grown WS2 on sapphire (TMDC-421)100 200 300 400 500010002000300040005000600070008000Intensity (a. u.)Raman Shift (cm-1) Raman of WS2 on sapphire E12gA1gooo550 600 650 700 75001000020000300004000050000600007000080000Intensity (a. u.)Wavelength (nm) PL of WS2 on sapphireFrom sapphire22/07/26-Yang-A BA excitonFigure S2: (A) Raman scattering and (B) PL spectra of an as-grown WS2 atomic layer on a c-planesapphire substrate. The spectra were measured at room temperature.Figure S1B shows photoluminescence (PL) spectrum; a red box surrounds the PL coming fromthe ions in the sapphire substrate. The PL originating from the A exciton had a peak at 625 nm.S-2S3. Analysis of Confocal PL ImagesS1楊さんからのデータをトリミングして、そのまま転載C:¥ActiveMine¥Photonic¥2D_materials_on_MSFs¥Raman and PL of as-grown WS2 on sapphire_220726.pdfS2D:¥Exp_data¥2023¥20230113_CFLM_enhPL(3)_WS2_on_SOI-MSF¥2023_01_13_10_18_48--enhPL(3)_WS2_on_SOI-MSF_after_RTA_20230113¥TileScan 2¥Posi1_C00_red_max10_with_ROI_0823-0503.JPGFigure S3: Analysis setting of confocal PL image. Box indicates the analyzed area for the photon-number distribution in Figure 3C. Note that the color of the image is pseudo-color and the originalis gray-scale.Figure S3 shows the confocal PL image, identical to Figure 3B, together with an analyzing boxfor the photon-number distribution (Figure 3C). The box contained 39644 pixels, being set to avoidrifts and holes as possible in the TMDC atomic layer. We note that the photon-number distributionwas not affected significantly by the setting of the box. The confocal image is gray-scale and shownwith a pseudo-color; the color is different from that in Figure 3B.S4. On-Top Electric-Field IntensityFigure S4 shows electric-field intensities in the optical configuration of Figure 2. The xy sectionswere set to be 0.5 nm above the top of the Si nanopellet. White circles indicate the position of Sinanopellet in the unitcell. Incident field was set to 1.0.Figure S4A shows that the electric-field intensity at 532 nm (i.e., excitation wavelength) is en-hanced by 5.3-fold at the maximum, and Figure S4B shows that at 608.9 nm, where the reflectanceS-3A B0127.005.3S3A  C:¥ActiveMine¥F90¥CyberSC¥AOBA¥SOI-MSFs¥EM-fields_SOI-MSF_a400d228_since20230513.pxp  230605a_e4B  ibid¥EM-fields_SOI-MSF_a400d228_since20230513.pxp  230605e_e2Figure S4: Electric-field intensity at 0.5 nm above the top of Si nanopellet: xy-section view. (A)532.0 nm. (B) 608.9 nm. Incident intensity was set to 1.0.takes a peak and the PL was largely enhanced (Figure 3A). In the latter, the maximum is 55.6 andthe resonant field is quite stronger than the incident field.S5. Purcell Effect: A Numerical ApproachA BS4A  C:¥ActiveMine¥Photonic¥2D_materials_on_MSFs¥Simulation_Data_from_Vasili_221216_final.pptx    slide 25B  ibid slide 25C ibid Vasili_FigureS4C.pngCFigure S5: Theoretical evaluation of Purcell factors. (A) Coordinate configuration for the unitcell.(B) Total Purcell factors at x and z polarizations, shown with red and blue curves, respectively.The factors are plotted for the right axis. Normalized reflection spectrum is also shown with blackcurve. (C) Purcell (or enhancement) factors are shown in a decomposed manner into radiative andnonradiative parts. Green curve corresponds to the experimental condition.Theoretical setting for Purcell-factor evaluation is described in the text (Methods section). Fig-ure S5A shows the coordinate configuration. A two-level oscillator was set to be placed at the centerof Si nanopellet above 2 nm from the top circular surface.Figure S5B presents reflection spectra (black) plotted for the left axis and total Purcell factorsS-4at x and z polarizations (red and blue, respectively) plotted for the right axis. The total factorscontain both radiative and nonradiative components. The experimentally observed Purcell factor(or enhancement factor) corresponds to a x-polarized radiative component shown with a green curvein Figure S5C. The realistic factor takes values around 2 in 600–650 nm. Note that the total Purcellfactor (dotted line) in Figure S5C is identical to that at x polarization (red) in Figure S5B.S6. Transfer Procedure of TMDC MonolayerWhen transferring the TMDC monolayer, we used polymethyl methacrylate (PMMA) film for pro-tection. As described in the text (section 4.2), the PMMA was spin-coated on the as-grown TMDCfilm on the sapphire substrate. Immersing the substrate in water, the TMDC and PMMA film waspeeled out together from the substrate. This peeled-out film was placed on the metasurface, whichis schematically illustrated in Figure S6A (left). Via van der Waals force, the film and the meta-surface substrate are absorbed. The PMMA protection film (light gray) was removed in acetone at50 ◦C for 1 h (Figure S6A, center). Thus, we obtained the transferred TMDC film (yellow) on themetasurface (Figure S6A, right). Note that the metasurface under the TMDC film is omitted in thedrawing. The sample in this study is schematically illustrated in a 3D view (Figure S6B); in reality,the atoms on the metasurface of Si-nanopellet array are much smaller than the Si nanopellets.A RemovalPlace monolayer with PMMA filmPMMATMDCTransferred monolayerBFigure S6: (A) TMDC monolayer (yellow) is protected using a PMMA film. The protection filmis removed using organic solvent and transferred monolayer is prepared. (B) 3D-view illustrationof TMDC-monolayer transferred on a metasurface of Si nanopellet array. Yellow spheres denote Satoms and gray ones W atoms.S-5References(S1) X. An, W. Zhao, Y. Yu, et.al., Resonance Raman scattering on graded-compositionWxMo1−xS2 alloy with tunable excitons. Appl. Phys. Lett., vol. 120, no. 17, p. 172104, 2022.S-6