Resistivity of thiol-modified gold thin films

Correa-Puerta, Jonathan; Campo, Valeria del; Henríquez, Ricardo; Häberle, Patricio

doi:10.1016/j.tsf.2014.09.033

Cited by 7 publications

(5 citation statements)

References 30 publications

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“…Scanning electron micrographs of single-layer graphene transferred onto Au shows Morphological characterization of samples before C. metallidurans exposure was carried out by SEM (Figure 2b,c). Uncoated Au samples showed a continuous film composed of percolated irregular-shaped grains with flat tops, as described in the literature [70]. Scanning electron micrographs of single-layer graphene transferred onto Au shows a smoother surface with the presence of wrinkles crossing sample's surface.…”

Section: Characterization Of Graphene-coated and Uncoated Au Samplessupporting

confidence: 71%

Graphene Coating as an Effective Barrier to Prevent Bacteria-Mediated Dissolution of Gold

Parra

Aristizábal

Arce

et al. 2021

Metals

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The interaction of biofilms with metallic surfaces produces two biologically induced degradation processes of materials: microbial induced corrosion and bioleaching. Both phenomena affect most metallic materials, but in the case of noble metals such as gold, which is inert to corrosion, metallophilic bacteria can cause its direct or in direct dissolution. When this process is controlled, it can be used for hydrometallurgical applications, such as the recovery of precious metals from electronic waste. However, the presence of unwanted bioleaching-producing bacteria can be detrimental to metallic materials in specific environments. In this work, we propose the use of single-layer graphene as a protective coating to reduce Au bioleaching by Cupriavidus metallidurans, a strain adapted to metal contaminated environments and capable of dissolving Au. By means of Scanning Tunneling Microscopy, we demonstrate that graphene coatings are an effective barrier to prevent the complex interactions responsible for Au dissolution. This behavior can be understood in terms of graphene pore size, which creates an impermeable barrier that prevents the pass of Au-complexing ligands produced by C.metallidurans through graphene coating. In addition, changes in surface energy and electrostatic interaction are presumably reducing bacterial adhesion to graphene-coated Au surfaces. Our findings provide a novel approach to reduce the deterioration of metallic materials in devices in environments where biofilms have been found to cause unwanted bioleaching.

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Section: Characterization Of Graphene-coated and Uncoated Au Samplessupporting

confidence: 71%

Graphene Coating as an Effective Barrier to Prevent Bacteria-Mediated Dissolution of Gold

Parra

Aristizábal

Arce

et al. 2021

Metals

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“…The surface is composed of domains with different molecular arrangements. As shown in panels b and c, two kinds of molecular superstructures c (4√3 × 2√3) R 30 and (√3 × √3) R 30 ,− have been identified. In addition to these reconstructions, the topographic image also shows the existence of dark regions, roughly 5 nm in diameter, which correspond to Au “vacancy islands”.…”

Section: Resultsmentioning

confidence: 86%

Unoccupied Interface and Molecular States in Thiol and Dithiol Monolayers

et al. 2017

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The electronic structure of self-assembled monolayers (SAMs) formed by thiols of different lengths and dithiol molecules bound to Au(111) has been characterized. Inverse photoemission spectroscopy (IPES) and density functional theory have been used to describe the molecule/Au substrate system. All molecular layers display a clear signal in the IPES data at the edge of the lowest unoccupied system orbital (LUSO), roughly 3 eV above the Fermi level. There is also evidence, in both the experimental data and the calculation, of a finite density of states just below the LUSO edge, which has been recognized as localized at the Au-substrate interface. Regardless of the molecular lengths and in addition to this induced density of interface states, an apparent antibonding Au-S state has been identified in the IPES data for both molecular systems. The main difference between the electronic structures of thiol and dithiol SAMs is a shift in the energy of the antibonding state.

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“…Figure 3(b) shows the thickness dependence of the ratio of resistivity changes to nanosheet resistivity without SAM modification ( ) / / r r D w o SAM in comparison with literature values. [17][18][19]28,30) The results are also summarized in Table II.…”

Section: Characterizationmentioning

confidence: 98%

“…/ / r r D w o SAM clearly depended on the thickness, which agreed with the previous studies. 17,19,42) The dashed lines in Fig. 3…”

Section: Characterizationmentioning

confidence: 99%

“…In a conventional model first developed by Fuchs and Sondheimer, 15,16) the effect of surface scatterings on the resistivity is introduced through a phenomenological specularity parameter P. This specularity parameter P represents the fraction of conduction electrons scattered specularly at the metal film surface, and it takes the value from = P 0 for completely diffusive scatterings to = P 1 for completely specular scatterings. Several research groups have modeled the resistivity changes induced by adsorbates using this parameter P. 2,[17][18][19][20][21][22] Some have provided the relationship between P and the coverage of adsorbates on a metal surface. [20][21][22] However, these quantitative results have only been obtained at a single temperature; room temperature (RT), and it has never been demonstrated whether P only depends on the coverage and P is independent of temperature.…”

Section: Introductionmentioning

confidence: 99%

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Temperature dependence of resistivity increases induced by thiols adsorption in gold nanosheets

Kato

Tanaka

Yajima

et al. 2021

Jpn. J. Appl. Phys.

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By utilizing stable thiol self-assembled monolayers (SAMs) on gold (Au) nanosheets, we investigated the temperature dependence of the amount of resistivity increases Δ ρ ad by SAM modification. Δ ρ ad increased with increasing temperature from 5 to 375 K in all the measured nanosheets for various thicknesses (9–20 nm). We consider from the DFT calculation that the temperature dependence originates from unoccupied states of sulfur atoms above the Fermi level of Au. The available unoccupied states increase at higher temperatures, which enhances scattering rates and thus increases the resistivity. Furthermore, we calculated the temperature dependence of Δ ρ ad using the Bloch–Grüneisen theory and Fuchs–Sondheimer (FS) model. Based on the results, we conclude that for ultra-thin metal films, the temperature-dependent specularity parameter P T which represents the fraction of electrons scattered specularly should be introduced into the conventional FS model to predict Δ ρ ad over a wide temperature range.

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Resistivity of thiol-modified gold thin films

Cited by 7 publications

References 30 publications

Graphene Coating as an Effective Barrier to Prevent Bacteria-Mediated Dissolution of Gold

Graphene Coating as an Effective Barrier to Prevent Bacteria-Mediated Dissolution of Gold

Unoccupied Interface and Molecular States in Thiol and Dithiol Monolayers

Temperature dependence of resistivity increases induced by thiols adsorption in gold nanosheets

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