Predicting the Surface Plasmon Resonance Wavelength of Gold–Silver Alloy Nanoparticles

• Published in: Journal of physical chemistry. C Vol. 117; no. 37; pp. 19142 - 19145
• Main Authors: Verbruggen, Sammy W, Keulemans, Maarten, Martens, Johan A, Lenaerts, Silvia
• Format: Journal Article
• Language: English
• Published: Columbus, OH American Chemical Society 19.09.2013
• Subjects: Collective effects; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electron states; Exact sciences and technology; Exchange, correlation, dielectric and magnetic functions, plasmons; Materials science; Nanoscale materials and structures: fabrication and characterization; Other topics in nanoscale materials and structures; Physics; Particle size; Experimental data; Gold alloys; Colloids; Nanostructures; Nanoparticles; Silver; Plasmons; Ultraviolet visible spectrum; Chemical composition; Surface plasmon resonance; Plasmonics; Permittivity; Nanostructured materials
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp4070856

Gold–silver alloy nanoparticles display surface plasmon resonance (SPR) over a broad range of the UV–vis spectrum. We propose a model to predict the SPR wavelength of gold–silver alloy colloids based on the combined effect of alloy composition and particle size. The SPR wavelength is derived from extinction spectra simulated using available experimental dielectric constant data and accounts for particle size by applying Mie theory. Comparison of calculated values with experimental data evidences the accuracy of the model. The new SPR wavelength estimation tool will be of particular interest for developing dedicated bimetallic plasmonic nanostructures.