Infrared surface plasmons in two-dimensional silver nanoparticle arrays in silicon

Abstract

We present two-dimensional arrays of silver nanoparticles embedded in amorphous silicon, fabricated by a sequential Si∕Ag∕Si electron-beam evaporation process. The particle arrays exhibit surface plasmon resonance spectra in the near-infrared (0.9eV), with tails extending below 0.5eV. The data are compared with calculations that take into account measured particle size, shape anisotropy, and separation. It is concluded that the large redshift is mainly due to the high refractive index of the matrix, with shape anisotropy and interparticle coupling contributing several tenths of an electron volt. This work enables plasmon-related applications at the telecommunication wavelength of 1.5μm(0.8eV).

Metal‐dielectric nanostructures for amplified Raman and fluorescence spectroscopy

“…3, reflectance spectra evidence an increase of the wavelength red shift of the LSP resonance by increasing the thickness of the dielectric shell. This behaviour is in agreement with theory and experimental findings reported in previous works dealing with the influence of the surrounding dielectric matrix on the particle plasmonic response [6,10]. In detail, the LSP resonance shifts from 363 nm for bare silvered porous silicon up to 510 nm for the nanostructure coated by a-SiN layer, 60 nm thick.…”

Improved light absorption in thin-film silicon solar cells by integration of silver nanoparticles

“…The spectral range of the observed absorption losses fits with the losses of individual Ag nanoparticles. Depending on the size of the particles and the embedding material, plasmon absorption losses can be found between 500 nm and 2 lm [16,17]. When the Ag surface is embedded in a material with a smaller refractive index in comparison to silicon (n $ 4), the surface plasmons of Ag can be shifted to smaller wavelengths and the absorption losses are reduced.…”

Controlling electronic properties of epitaxial nanocomposites of dissimilar materials

“…The most well-developed application has been surface enhanced Raman spectroscopy [56] in which the enhanced local fields near metallic particles, due to the plasmon resonance, boost the spectroscopic signal of near by molecules. Embedding metal particles in higher index materials such as semiconductors is known to push the resonance toward the infrared [57][58][59][60] and provide the possibility of integrating plasmonbased functions with traditional semiconductor devices. Applications more relevant to metal/semiconductor composites such as photodetectors [61,62] and solar cells [63][64][65] are also being investigated in an effort to use the field enhancement associated with the plasmon resonance to increase absorption [66].…”