Abstract
Objective: The localized surface plasmon resonance (LSPR) and field enhancement of multilayered nanostructure over single and dimer configuration is studied using finite difference time domain (FDTD) method.
Experimental: In multilayered nanostructure, there exist concentric nanoshells and metallic core which are separated by a dielectric layer. Strong couplings between the core and nanoshell plasmon resonance modes show a shift in LSPR and enhancement in field around nanostructure. The calculation of the electric field enhancement shows a sharp increase in the electric field on the surface of inner core i.e., inside the dielectric layer of Metal-Dielectric-Metal (MDM) structure whereas smaller enhancement on the outer layer of MDM structure is observed.
Results: The Au-Air-Au mono MDM nanostructure shows strong near-field enhancement as compared to bare nanosphere in the infrared region, which have potential applications in surfaceenhanced spectroscopy, whereas Al-Air-Al and Ag-Air-Ag shows potential towards lower wavelength region. On coupling the MDM nanostructure forming a dimer configuration the field enhancement factor increases to 10^8.
Conclusion: As compared to other nanostructures, MDM nanostructure provides both strong field enhancement and wide wavelength tunability therefore promising for surface enhanced Raman spectroscopy (SERS) applications.
Keywords: Multilayered nanostructure, field enhancement, localized surface plasmon resonance, FDTD, MDM, nanoshell plasmon resonance.
Graphical Abstract
[http://dx.doi.org/10.1021/jp026731y]
[http://dx.doi.org/10.1007/BF01393059]
[http://dx.doi.org/10.1126/science.1114849] [PMID: 16410515]
[http://dx.doi.org/10.1021/ac053456d]
[http://dx.doi.org/10.1364/OE.16.021793] [PMID: 19104612]
[http://dx.doi.org/10.1126/science.1133628] [PMID: 17053110]
[http://dx.doi.org/10.1021/nl072377+] [PMID: 18034505]
[http://dx.doi.org/10.1039/c0nr00028k] [PMID: 20644772]
[http://dx.doi.org/10.1364/OE.19.005587] [PMID: 21445198]
[http://dx.doi.org/10.1515/nanoph-2016-0124]
[http://dx.doi.org/10.1364/OE.14.004842] [PMID: 19516642]
[http://dx.doi.org/10.1021/nl502416b] [PMID: 25211306]
[http://dx.doi.org/10.1038/ncomms7939] [PMID: 25891212]
[http://dx.doi.org/10.2147/nano.2006.1.1.73] [PMID: 17722264]
[http://dx.doi.org/10.1364/OE.19.026186] [PMID: 22274205]
[http://dx.doi.org/10.1021/nl049597x]
[http://dx.doi.org/10.1126/science.1089171] [PMID: 14564001]
[http://dx.doi.org/10.1007/s00340-009-3432-0]
[http://dx.doi.org/10.1021/jp1001034]
[http://dx.doi.org/10.1557/adv.2016.7]
[http://dx.doi.org/10.1186/1556-276X-6-279] [PMID: 21711793]
[http://dx.doi.org/10.1007/s11468-014-9728-x]
[http://dx.doi.org/10.1021/jp8060009]
[http://dx.doi.org/10.1109/TNANO.2010.2079943]
[http://dx.doi.org/10.3390/s130911350] [PMID: 24064596]
[http://dx.doi.org/10.1002/jrs.1357]
[http://dx.doi.org/10.1021/nl903563e] [PMID: 20028028]
[http://dx.doi.org/10.1007/s11468-015-9991-5]