| AVS 54th International Symposium | |
| Plasmonics Topical Conference | Tuesday Sessions |
| Session PL-TuP |
| Session: | Plasmonics Poster Session |
| Presenter: | R. Bukasov, University of Utah |
| Authors: | R. Bukasov, University of Utah J.S. Shumaker-Parry, University of Utah |
| Correspondent: | Click to Email |
Gold crescent-shaped nanostructures with uniform size and orientation were fabricated using nanosphere template lithography. The nanocrescents have broadly tunable (900-3600 nm) and strong plasmon resonances (effective cross sections up to 30). The plasmons resonances in the crescents have been shown to be sensitive to the dielectric environment with shifts of the plasmon resonance peak position of up to 880nm/RIU. We will present a new approach to investigate the tunability of nanocrescent plasmons in the infrared (IR) spectral region based on controlling the distance between the tips of the open crescent structures. The tip-to-tip distances in the nanocrescents were varied until a continous ring formed. The crescents were fabricated by controlling the angle of deposition and the angle of rotation between subsequent metal depositions. The number of plasmon resonance peaks in the IR increases from two for completely open crescents to four peaks for closed, continuous crescents. The magnitude of those resonances is dependent upon the orientation of the nanocrescents with respect to the polarization of the incident light. The application of the crescents as a tunable substrates for surface-enhanced infrared absorption (SEIRA) spectroscopy is being investigated. The ability to tune the crescent plasmon resonances farther into the IR by using substrates with higher refractive indices (e.g., from a refractive index of ~ 1.5 for glass to ~3.4 for silicon) is being explored.