Interface second harmonic generation enhancement in bulk WS2/MoS2 hetero-bilayer van der Waals nanoantennas
Year: 2025
Authors: Tognazzi A., Franceschini P., Biechteler J., Basch E., Cino A.C., Tittl A., De Angelis C., Sortino L.
Autors Affiliation: Univ Palermo, Dept Engn, Viale Sci, I-90128 Palermo, Italy; Natl Res Council INO CNR, Natl Inst Opt, Via Branze 45, I-25123 Brescia, Italy; Univ Brescia, Dept Informat Engn, Via Branze 38, I-25123 Brescia, Italy; Ludwig Maximilians Univ Munchen, Fac Phys, Chair Hybrid Nanosyst, Nanoinst Munich, D-80539 Munich, Germany.
Abstract: Layered van der Waals (vdW) materials have emerged as a promising platform for nanophotonics due to large refractive indexes and giant optical anisotropy. Unlike conventional dielectrics and semiconductors, the absence of covalent bonds between layers allows for novel degrees of freedom in designing optically resonant nanophotonic structures down to the atomic scale: from the precise stacking of vertical heterostructures to controlling the twist angle between crystallographic axes. Specifically, although monolayers of transition metal dichalcogenides exhibit giant second-order nonlinear responses, their bulk counterparts with 2H stacking possess zero second-order nonlinearity. In this work, we investigate second harmonic generation (SHG) arising from the interface of WS2/MoS2 hetero-bilayer thin films with an additional SHG enhancement in nanostructured optical antennas, mediated by both the excitonic resonances and the anapole-driven field enhancement. When both conditions are met, we observe up to 102 SHG signal enhancement, compared to unstructured bilayers, with SHG conversion efficiency reaching approximate to 10-7. Our results highlights vdW materials as a platform for designing unique multilayer optical nanostructures and metamaterial, paving the way for advanced applications in nanophotonics and nonlinear optics.
Journal/Review: LIGHT-SCIENCE & APPLICATIONS
Volume: 14 (1) Pages from: 346-1 to: 346-8
More Information: Funded by the European Union (ERC, METANEXT, 101078018 and EIC, NEHO, 101046329). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union, the European Research Council Executive Agency, or the European Innovation Council and SMEs Executive Agency (EISMEA). Neither the European Union nor the granting authority can be held responsible for them. This work was also funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy (EXC 2089/1 – 390776260), Sachbeihilfe MA 4699/7-1 and the Emmy Noether program (TI 1063/1); the Bavarian program Solar Energies Go Hybrid (SolTech) and the Center for NanoScience (CeNS). L.S. acknowledges funding support through a Humboldt Research Fellowship from the Alexander von Humboldt Foundation. A.To. acknowledges the financial support from the European Union through FESR o FSE, PON Ricerca e Innovazione 2014-2020 – DM 1062/2021 and the University of Palermo through Fondo Finalizzato alla Ricerca di Ateneo 2024 (FFR2024). This work was partially supported by the European Union under the Italian National Recovery and Resilience Plan (NRRP) of NextGenerationEU, of partnership on Telecommunications of the Future (PE00000001 – program RESTART), S2 SUPER – Programmable Networks, Cascade project PRISM – CUP: C79J24000190004. C.D.A. and P.F. acknowledge the financial support from the European Union METAFAST H2020-FETOPEN-2018-2020 project, grant agreement no. 899673; from Ministero Italiano dell’Istruzione (MIUR) through the METEOR project PRIN-2020 2020EY2LJT_002.DOI: 10.1038/s41377-025-01983-yCitations: 1data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2025-10-26References taken from IsiWeb of Knowledge: (subscribers only)
