Tuning the effective dielectric function of thin film metal-dielectric composites by controlling the deposition temperature

Abstract

Abstract. The influence of the substrate temperature on the effective optical behavior of Ag-SiO 2 composites obtained by electron beam evaporation was studied. Optical characterization of the composites was performed by means of spectroscopic ellipsometry measurements. The effective dielectric function of the composites, modeled using a multiple oscillator approach, could be widely tuned by controlling the deposition temperature. The spectral dependence of the composite absorption appeared to be better described with a Gaussian line shape than with the classical Lorentz oscillator model. The description of the effective dielectric function using standard effective medium theories failed and the experimental results could be explained only in the general framework of the Bergman spectral density theory. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).

Metal island film-based structures for sensing using spectrophotometry and ellipsometry

“…Base pressure was 6 · 10 −6 Torr. Prior to the deposition of Au island film the samples were preheated to 250 o C to enhance metal island growth [14,15]. Mass thickness of the layers was controlled by a quartz crystal monitor.…”

“…2.). Since effective medium theories were shown inadequate to describe dielectric functions of MIF, they are modelled with Gauss oscillators [15,18]. The optical parameters of dielectric constants (real and imaginary part, ε1 and ε2) of this layer are modelled with a sum of 5 Gauss oscillators.…”

Design and production of bicolour reflecting coatings with Au metal island films

“…If the metal clusters are small compared to the wavelength of the incidence light, it is possible to describe their optical behaviour using effective optical constants and thickness that can be determined from experimental measurements [10][11][12][13][14]. The effective optical constants in the visible range are governed by the SPR, with a strong absorption peak and the associated dispersion of refractive index.…”

Comparison of two techniques for reliable characterization of thin metal–dielectric films

“…The most popular technique is based on a well-known oscillator model [23][24][25]. However, wavelength dependencies of the optical constants of thin metal-dielectric films in the visible and infrared spectral ranges are quite complicated [1,[7][8][9]13,[26][27][28], and multiple oscillator models have to be used.…”

“…However, wavelength dependencies of the optical constants of thin metal-dielectric films in the visible and infrared spectral ranges are quite complicated [1,[7][8][9]13,[26][27][28], and multiple oscillator models have to be used. Because each oscillator is defined by several parameters, a large number of parameters has to be determined in the course of the characterization process using a multiple oscillator model [23][24][25]29].…”