Properties of Thermally Dewetted Thin Au Films on ITO-Coated Glass for Biosensing Applications

Grochowska, Katarzyna; Siuzdak, Katarzyna; Karczewski, Jakub; Szkoda, Mariusz; Śliwiński, Gerard

doi:10.1007/s11468-016-0465-1

Cited by 4 publications

(9 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As the electric fields under such conditions do not have very strong field gradients, we expect moderate differences between using the proposed GEM averaging method and a classical MG approach. However, recent investigations of thermal dewetting of thin Au films into a nanoparticle layer [12] or the feasibility of antireflection coatings based on silver nanoparticle films [15] motivate our choice and showcase the realm of applicability of the GEM method.…”

Section: Resultsmentioning

confidence: 99%

“…Here, we consider situations outside the limits of applicability of the classical MG formula, that is when anisotropically distributed inclusions within a host medium are illuminated by an inhomogeneous electric field. A typical example, where such conditions occur are thin nanoparticle layers supported by interfaces [12, 15, 43], where the presence of the interface breaks symmetry and introduces electric field gradients (see Fig. 1a).…”

Section: Methods—gradient Effective Permittivity Modelmentioning

confidence: 99%

“…Modeled structures are placed on a substrate with a refractive index of 1.45. The parameters of discontinuous Pd nanoparticle layers are initially based on those fabricated for the work of Adibi et al [10], but subsequently tested mean radii and their standard deviations are probed in a broad range, as can be observed in other experiments [12]. The initial equivalent mass thickness is assumed to be 0.5 nm [10].…”

Section: Methods—gradient Effective Permittivity Modelmentioning

confidence: 99%

“…A good example of such a modeling problem is an indirect nanoplasmonic sensing (INPS) experiment [8] in which a metal nanoantenna, whose immediate vicinity is filled with smaller nanoparticles [9], interrogates their material and/or chemical changes of and reports them via a peak shift [10, 11]. The challenge lies in the fact that the nanoparticles, which constitute the sensed element, are random in both size, position, and shape [12] and in simulations; it is all but impossible to model even a small fraction of plasmonic sensors interrogated in an actual experiment.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Effective Optical Properties of Inhomogeneously Distributed Nanoobjects in Strong Field Gradients of Nanoplasmonic Sensors

et al. 2018

View full text Add to dashboard Cite

Accurate and efficient modeling of discontinuous, randomly distributed entities is a computationally challenging task, especially in the presence of large and inhomogeneous electric near-fields of plasmons. Simultaneously, the anisotropy of sensed entities and their overlap with inhomogeneous fields means that typical effective medium approaches may fail at describing their optical properties. Here, we extend the Maxwell Garnett mixing formula to overcome this limitation by introducing a gradient within the effective medium description of inhomogeneous nanoparticle layers. The effective medium layer is divided into slices with a varying volume fraction of the inclusions and, consequently, a spatially varying effective permittivity. This preserves the interplay between an anisotropic particle distribution and an inhomogeneous electric field and enables more accurate predictions than with a single effective layer. We demonstrate the usefulness of the gradient effective medium in FDTD modeling of indirect plasmonic sensing of nanoparticle sintering. First of all, it yields accurate results significantly faster than with explicitly modeled nanoparticles. Moreover, by employing the gradient effective medium approach, we prove that the detected signal is proportional to not only the nanoparticle size but also its size dispersion and potentially shape. This implies that the simple volume fraction parameter is insufficient to properly homogenize these types of nanoparticle layers and that in order to quantify optically the state of the layer more than one independent measurement should be carried out. These findings extend beyond nanoparticle sintering and could be useful in analysis of average signals in both plasmonic and dielectric systems to unveil dynamic changes in exosomes or polymer brushes, phase changes of nanoparticles, or quantifying light absorption in plasmon assisted catalysis.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methods—gradient Effective Permittivity Modelmentioning

confidence: 99%

Section: Methods—gradient Effective Permittivity Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effective Optical Properties of Inhomogeneously Distributed Nanoobjects in Strong Field Gradients of Nanoplasmonic Sensors

et al. 2018

View full text Add to dashboard Cite

show abstract

“…[14][15][16][17] The optical response of Au films is strongly sensitive to its real space parameters (RSP's) like the sizes, shapes, number density of the nanoparticles and the covered area fractions (CAF) in the films along with its surrounding and the substrate material. 18,19 The average values, as well as the statistical distributions of all the RSP's of the films are important, which finally decides the optical response of Au thin films. 20 The fine tuning of optical response essentially demands the precisely controlled growth technique along with sub-nanometer scale morphological characterization.…”

Section: Introductionmentioning

confidence: 99%

A study of growth and thermal dewetting behavior of ultra-thin gold films using transmission electron microscopy

Sudheer

Mondal

et al. 2017

AIP Advances

View full text Add to dashboard Cite

The growth and solid-state dewetting behavior of Au thin films (0.7 to 8.4 nm) deposited on the formvar film (substrate) by sputtering technique have been studied using transmission electron microscopy. The size and number density of the Au nanoparticles (NPs) change with an increase in the film thickness (0.7 to 2.8 nm). Nearly spherical Au NPs are obtained for <3 nm thickness films whereas percolated nanostructures are observed for ≥3 nm thickness films as a consequence of the interfacial interaction of Au and formvar film. The covered area fraction (CAF) increases from ∼13 to 75 % with the change in film thickness from 0.7 to 8.4 nm. In-situ annealing of ≤3 nm film produces comparatively bigger size and better sphericity Au NPs along with their narrow distributions, whereas just percolated film produces broad distribution in size having spherical as well as elongated Au NPs. The films with thickness ≤3 nm show excellent thermal stability. The films having thickness >6 nm show capability to be used as an irreversible temperature sensor with a sensitivity of ∼0.1 CAF/°C. It is observed that annealing affects the crystallinity of the Au grains in the films. The electron diffraction measurement also shows annealing induced morphological evolution in the percolated Au thin films (≥3 nm) during solid-state dewetting and recrystallization of the grains.

show abstract

Temperature-controlled nanomosaics of AuCu bimetallic structure towards smart light management

Lipińska

Grochowska

Karczewski

et al. 2022

J Mater Sci: Mater Electron

Self Cite

View full text Add to dashboard Cite

Gold–copper nanostructures are promising in solar-driven processes because of their optical, photocatalytic and photoelectrochemical properties, especially those which result from the synergy between the two metals. Increasing interest in their internal structure, such as the composition or distribution of the Au and Cu as well as the size and shape of the nanoparticles, have developed to define their physicochemical properties.In this work, we present the influence of thermal treatment in temperature ranges from 100 to 600 °C on the formation process of bimetallic AuCu structures and their properties. AuCu materials were placed on nanostructured titanium foil substrates that were fabricated using electrochemical anodisation and chemical etching. Thin layers of AuCu mixture, as well as Au and Cu, were sputtered on the obtained Ti nanodimples. The materials were then annealed in a rapid thermal annealing furnace in an air atmosphere. Thermal treatment strongly affected the morphology and optical properties of the fabricated materials. AuCu NPs formed at 400 °C in titanium dimples. The material exhibits absorption of visible light in the range from c.a. 400 to 700 nm. The characterisation of the chemical nature of the samples was determined using X-ray photoelectron spectroscopy. In addition, X-ray diffraction and Raman spectroscopy defined composition and crystallinity. Based on photoelectrochemical studies carried out with the use of linear voltammetry in 0.1 M NaOH, it is possible to distinguish two types of interactions of light with the materials such as photogenerated charge accumulation and electron–hole pair separation. A 10AuCu electrode annealed at 300 °C achieved the highest current registered under illumination at − 0.17 V vs. Ag/AgCl/0.1 M KCl. The value was 11 times higher than for a non-annealed structure.

show abstract

Properties of Thermally Dewetted Thin Au Films on ITO-Coated Glass for Biosensing Applications

Cited by 4 publications

References 43 publications

Effective Optical Properties of Inhomogeneously Distributed Nanoobjects in Strong Field Gradients of Nanoplasmonic Sensors

Effective Optical Properties of Inhomogeneously Distributed Nanoobjects in Strong Field Gradients of Nanoplasmonic Sensors

A study of growth and thermal dewetting behavior of ultra-thin gold films using transmission electron microscopy

Temperature-controlled nanomosaics of AuCu bimetallic structure towards smart light management

Contact Info

Product

Resources

About