1. Plasmonic Nanocrystal Arrays on Photonic Crystals with Tailored Optical Resonances
- Author
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Jan C.T. Eijkel, Theodosios D. Karamanos, Carsten Rockstuhl, Lingling Shui, Hai Le-The, Albert van den Berg, Loes I. Segerink, Pepijn W. H. Pinkse, Radius N. S. Suryadharma, Juan Wang, Biomedical and Environmental Sensorsystems, Physics of Fluids, Laser Physics & Nonlinear Optics, and Complex Photonic Systems
- Subjects
Materials science ,02 engineering and technology ,Stopband ,Plasmonic−photonic microsphere ,010402 general chemistry ,01 natural sciences ,symbols.namesake ,General Materials Science ,Surface plasmon resonance ,Plasmon ,Photonic crystal ,business.industry ,Slow light effect ,Surface-enhanced Raman spectroscopy ,Photonic stop band ,Localized surface plasmon resonance ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Nanocrystal ,symbols ,Optoelectronics ,Photonics ,0210 nano-technology ,Raman spectroscopy ,business ,Research Article - Abstract
Hierarchical plasmonic–photonic microspheres (PPMs) with high controllability in their structures and optical properties have been explored toward surface-enhanced Raman spectroscopy. The PPMs consist of gold nanocrystal (AuNC) arrays (3rd-tier) anchored on a hexagonal nanopattern (2nd-tier) assembled from silica nanoparticles (SiO2NPs) where the uniform microsphere backbone is termed the 1st-tier. The PPMs sustain both photonic stop band (PSB) properties, resulting from periodic SiO2NP arrangements of the 2nd-tier, and a surface plasmon resonance (SPR), resulting from AuNC arrays of the 3rd-tier. Thanks to the synergistic effects of the photonic crystal (PC) structure and the AuNC array, the electromagnetic (EM) field in such a multiscale composite structure can tremendously be enhanced at certain wavelengths. These effects are demonstrated by experimentally evaluating the Raman enhancement of benzenethiol (BT) as a probe molecule and are confirmed via numerical simulations. We achieve a maximum SERS enhancement factor of up to ∼108 when the resonances are tailored to coincide with the excitation wavelength by suitable structural modifications.
- Published
- 2020