Active Ag-Co Composite Chiral Nanohole Arrays
Updated: May 7, 2021
J. Phys. Chem. C 2021, 125, 716–723.
The magneto-chiroptical properties of Ag/Co composite chiral nanohole arrays (CCNAs) are investigated. The intrinsic circular dichroism of CCNA samples was induced by in-plane symmetry breaking by a glancing angle deposition method, and it can be enhanced strongly by surface plasmon resonance when Ag is a major component. On the other hand, the Co component allows for magnetic tuning circular dichroism, with the maximum modulation amplitude up to 0.35°. Remarkably, the enhanced local electric field induced by Wood’s anomalies gives rise to sharper and stronger magnetic circular dichroism (normalized for the same Co content) of samples with high Ag concentration. The result demonstrates the possibility of fabricating large-scale active chiroptical metasurfaces using CCNAs, which is promising for imaging and sensing applications.