Double-exponential refractive index sensitivity of metal-semiconductor core-shell nanoparticles

• Verfasst von: Zhang, Hailong [VerfasserIn]
• Verfasst von: Cao, Pengfei [VerfasserIn]
• Titel: Double-exponential refractive index sensitivity of metal-semiconductor core-shell nanoparticles
• Titelzusatz: the effects of dual-plasmon resonances and red-shift
• Verf.angabe: Hailong Zhang, Pengfei Cao, Jie Dou, Lin Cheng, Tiaoming Niu and Guanmao Zhang
• E-Jahr: 2018
• Jahr: 05 Jan 2018
• Umfang: 6 S.
• Fussnoten: Gesehen am 31.03.2020
• Titel Quelle: Enthalten in: Royal Society of ChemistryRSC Advances
• Ort Quelle: London : RSC Publishing, 2011
• Jahr Quelle: 2018
• Band/Heft Quelle: 8(2018), 3, Seite 1700-1705
• ISSN Quelle: 2046-2069
• DOI: doi:10.1039/C7RA11981J
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1693586770

Abstract

In order to improve the refractive index sensitivity of a localized surface plasmon resonance (LSPR) sensor, we present a new type of LSPR sensor whose refractive index sensitivity can be improved by greatly increasing the plasmon wavelength red-shift of metal-semiconductor core-shell nanoparticles (CSNs). Using extended Mie theory and Au@Cu2−xS CSNs, we theoretically investigate the optical properties of metal-semiconductor CSNs in the entire near-infrared band. Compared with dielectric-metal and metal-metal CSNs under the same conditions, the metal-semiconductor CSNs have a higher double-exponential sensitivity curve because their core and shell respectively support two LSPRs that greatly increase the LSPR red-shift to the entire near-infrared range. It is worth noting that the sensitivity can be improved effectively by increasing the ratio of the shell-thickness to core-radius, instead of decreasing it in the case of the dielectric-metal CSNs. The underlying reason for the enhancement of sensitivity is the increase of repulsive force with the enlargement of shell thickness, which is different from the dielectric-metal CSNs. This design method not only paves the way for utilizing metal-semiconductor CSNs in biology and chemistry, but also proposes new ideas for the design of sensors with high sensitivity.