In recent years there has been a shift of interest in the Nanophotonics community moving from using metallic/plasmonic materials to using high-index dielectric materials for the construction of metasurfaces. Although high-index dielectrics hold many advantages over their plasmonic counterparts, the selection of materials that exhibit high-index properties, have low loss, and are complemetary metal-oxide-semiconductor (CMOS) compatible that also operate in the visible regime is extremely challenging. In this work, a high-index dielectric material using silicon rich nitride (SRN) is proposed and experimentally demonstrated as a platform for solving this problem. While SRN has been used before for diffractive lenses and structural colors, here its applicability for Huygens-type metasurfaces is focused upon. Specifically, a Huygens metasurface that operates in the visible range around a wavelength of 575 nm is theoretically and experimentally demonstrated, and the capabilities of spatially controlling the phase of this metasurface are further demonstrated by designing and fabricating a Huygens meta hologram. The study also shows that the refractive index can be controlled by the interplay between SiH4 and NH3 during the plasma-enhanced chemical vapor deposition (PECVD) process.
Bibliographical noteFunding Information:
The authors acknowledge partial support from the Israeli Innovation Authority. Samples were fabricated at the Center for Nanoscience and Nanotechnology of the Hebrew University of Jerusalem. The authors thank Maurice Saidian for support in the PECVD process.
© 2023 The Authors. Advanced Optical Materials published by Wiley-VCH GmbH.
- dielectric metasurfaces
- silicon rich nitride