The impact of loss on high-Q resonant metasurfaces: A case study for heated a-Si:H

• DOI: 10.1016/j.jqsrt.2022.108348
• Publication Date: 2022-08-20T01:42:34Z
• Authors: Angela Barreda; Athira Kuppadakkath; Lilit Ghazaryan; Ziyang Gan; Kirill Koshelev; Tobias Bucher; Thomas Pertsch; Antony George; Andrey Turchanin; Adriana Szeghalmi; Yuri Kivshar; Duk-Yong Choi; Isabelle Staude; Falk Eilenberger
• Keywords: Materiales; Hydrogenated amorphous silicon; Quasi-bound states in the continuum resonances; 0103 physical sciences; Optical losses; Electrónica; All-dielectric metasurfaces; 2D materials; 01 natural sciences; Óptica

The excitation of quasi bound states in the continuum (q-BIC) resonances has been demonstrated in the last years to be useful for lasing, non-linear effects, sensing, or photoluminescence enhancement. In par- ticular, the usage of q-BIC resonances in all-dielectric hydrogenated amorphous silicon (a-Si:H) metasur- faces for enhancing the light-matter interaction with 2D materials has been recently proposed. Growing 2D material directly on the metasurface requires heating to high temperatures, changing the metasurface optical properties (absorption increase). This fact makes necessary to consider the effect of losses on the excitation of q-BIC resonances. Here, we study the influence of absorption losses on the Q-factor values of an a-Si:H metasurface designed to exhibit a q-BIC resonance in the visible spectral region. As a concrete example, we investigate the consequences of heating the metasurface under investigation. We demon- strate that the increase in the optical losses decreases the Q-factor values or even prevents the excitation of the q-BIC resonance in the metasurface. This work may pave the way for the design of metasurfaces suitable for growing 2D materials directly on the metasurface. This integration scheme can resolve many challenges associated with the present transfer-based method for the coupling of 2D materials to meta- surfaces.<br/>This work was partly performed at the ACT node of the Australian National Fabrication Facility (ANFF-ACT). This work was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) through the International Research Training Group (IRTG) 2675 “Meta-ACTIVE”, project number 437527638, and the Collaborative Research Center (CRC 1375 NOA, projects B2 and B3). T. P. and I. S. thank the support from the European Union by project METAFAST-899673-FETOPEN-H2020. L.G. and A.S. acknowledge the financial support by the DFG (Project-ID 398816777), the Open Access Publication Fund of the Thüringer Universitäts - und Landesbibliothek Jena (Projekt-Nr.433052568). A.K. is supported by the European Union, the European Social Funds, and the Federal State of Thuringia as FGR 0088 under Grant ID 2018FGR00088. F.E. is supported by the Federal Ministry of Education and Science of Germany under Grant ID 13XP5053A.<br/>