Inelastic electron tunneling spectroscopy of triethoxysilane on germania: a model study for silane-glass adhesion

Mallik, Robert; Anabtawi, S.; Moore, B.; Hartman, T.A.

doi:10.1016/s0039-6028(97)00033-2

Cited by 8 publications

(5 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Studies of the TES/silica interaction have been recently reported, 22,23 mostly based on electrophoresis and magic angle spinning-nuclear magnetic resonance (MAS NMR) spectroscopy with some IR data; a study of the interaction of TES with germania, using inelastic electron tunneling spectroscopy (IETS), has also been published. 24 The results that we obtained with TES will allow us to interpret those obtained for the liquid-phase TESPT/silica interaction, therefore gaining information that can explain the behavior of the resulting filler/ rubber composite.…”

Section: Introductionmentioning

confidence: 66%

“…Moreover, it has the advantage of being volatile, therefore allowing gas/solid interaction, and it contains an easily IR-detectable and sensitive bond (the Si−H bond) whose stretching frequency can be used as a probe for the structure of the adsorbed species. Studies of the TES/silica interaction have been recently reported, , mostly based on electrophoresis and magic angle spinning−nuclear magnetic resonance (MAS NMR) spectroscopy with some IR data; a study of the interaction of TES with germania, using inelastic electron tunneling spectroscopy (IETS), has also been published . The results that we obtained with TES will allow us to interpret those obtained for the liquid-phase TESPT/silica interaction, therefore gaining information that can explain the behavior of the resulting filler/rubber composite.…”

Section: Introductionmentioning

confidence: 75%

See 1 more Smart Citation

A Fourier Transform Infrared (FTIR) Study of the Reaction of Triethoxysilane (TES) and Bis[3-triethoxysilylpropyl]tetrasulfane (TESPT) with the Surface of Amorphous Silica

et al. 2004

View full text Add to dashboard Cite

The interaction of triethoxysilane (TES) and bis [3-triethoxysilylpropyl]tetrasulfane (TESPT) with silica has been studied by IR spectroscopy. TES has been adsorbed onto silica pretreated at different temperatures, from the gas phase and, also, by a liquid-phase procedure. The analysis of the Si-H stretching and deformation modes, the C-H stretching and deformation modes, the SiO-H stretching, and the C-O-Si stretching modes has allowed us to investigate the structure of the adsorbed species and propose a chemisorption/desorption mechanism. The spectral features of hydrogen-bonded TES and those of three different chemisorbed species (with the formation of one, two, and three Si-O-silica bonds, respectively) have been identified. It has been concluded that the first interaction involves terminal free silanols, which actually exist also on the wet silica surface. The second and third Si-O-silica bonds are established by opening the nearest siloxane bridges. The silanization process is faster when performed in the liquid phase, because of the presence of some water in the reaction medium and the long time of reaction applied. The presence of a small amount of water promotes the adsorption reaction, likely by hydrolyzing the adsorbate. The spectroscopic data suggest that TESPT is bonded, after typical liquid-phase contact, through two Si-O-silica siloxane bridges with one remaining ethoxy group. The extent of polycondensation of the silanes seems very limited, if at all, under our conditions. IntroductionAmorphous silica 1 is an inexpensive and easily available commercial material that has many different industrial applications, including use as an adsorbent, a pigment, a catalyst support, a filler for rubber and other polymers, an electric insulator, an acoustic insulator, an optical material, and so on. It is also used for biological and pharmaceutical applications.Structurally, amorphous silica is a quite covalent oxide material 2 whose surface behavior is dominated by the chemistry of the terminal silanol groups 3 that are either isolated, vicinal, or geminal. 4 These groups, although being weakly Brønsted acidic, 5 are able to establish quite strong but easily reversible hydrogen bondings with polar molecules 6 that are the key phenomena occurring in adsorption-desorption cycles. Silanol groups lying nearby also make hydrogen bonds with each other, which results in chains of hydrogen-bonded hydroxyls 7 whose interaction with adsorbates is weaker than that of free silanols. 8 The silanols make the surface of hydroxylated silicas hydrophilic, and even more active in adsorption when wet. It is wellknown that hydrogen bondings also occur between the silica silanol groups and unpolar molecules such as hydrocarbons, 6,7,9 which allows silicas to be used for the adsorption of these compounds also. However, this interaction is weaker than that

show abstract

Section: Introductionmentioning

confidence: 66%

Section: Introductionmentioning

confidence: 75%

A Fourier Transform Infrared (FTIR) Study of the Reaction of Triethoxysilane (TES) and Bis[3-triethoxysilylpropyl]tetrasulfane (TESPT) with the Surface of Amorphous Silica

et al. 2004

View full text Add to dashboard Cite

show abstract

“…The structures and properties of these thin evaporated semiconductor films have been studied. 20,21,[103][104][105][106][107][108][109][110][111][112][113][114][115][116][117][118][119] Tunneling spectra of oxides grown on Si wafers were also reported. [120][121][122][123][124][125] …”

Section: Characterization Of Thin Semiconductor Filmsmentioning

confidence: 99%

“…Mallik et al 119 measured the tunneling spectra of thin (2 nm) GeO2 films prepared by radio frequency sputter deposition on Al. Though the tunneling spectra showed the peaks of νGe-Ge, νsGeOGe, and νasGeOGe at 270, 570 and 900 cm -1 , respectively, the spectra had no peaks due to GeHx.…”

Section: ·2 Germanium and The Oxidesmentioning

confidence: 99%

Characterization of Metal Oxide Surfaces and Thin Semiconductor Films by Inelastic Electron Tunneling Spectroscopy

Higo

Kamata

2002

ANAL. SCI.

View full text Add to dashboard Cite

“…Several techniques have been used to investigate these processes including x-ray photoelectron a͒ Author to whom correspondence should be addressed; electronic mail: rrm@physics.uakron.edu spectroscopy, 10 and deep level transient spectroscopy. 11 In this article, we use inelastic electron tunneling spectroscopy ͑IETS͒, which been used previously to study the vibrational spectra of ultrathin sputtered films of germanium oxide, 12 silicon and its oxides, 13,14 and evaporated silicon and its oxides. 15 In this technique, inelastic scattering of electrons tunneling through a thin-film barrier in a metal/barrier/metal tunnel junction is employed to excite vibrational, optical, and electronic modes in the barrier material.…”

Section: Spectroscopic Topological and Electronic Characterization mentioning

confidence: 99%

Spectroscopic, topological, and electronic characterization of ultrathin a-CdTe:O tunnel barriers

Dolog

Mallik

Malz

et al. 2004

Journal of Applied Physics

View full text Add to dashboard Cite

Auger electron spectroscopy analysis of oxidation states of Te in amorphous CdTe oxide thin films Ultrathin oxygenated amorphous CdTe (a-CdTe:O) films are prepared by rf sputtering of CdTe in a background of argon or argon/nitrogen/oxygen mixtures. Atomic force microscopy ͑AFM͒ is used to characterize the films and shows that they have an island structure typical of most sputtered thin films. However, when sufficiently low powers and deposition rates are employed during sputtering, the resulting films are remarkably smooth and sufficiently thin for use as barrier layers in inelastic electron tunneling ͑IET͒ junctions. Four terminal current-voltage data are recorded for Al/a-CdTe:O/Pb tunnel junctions and conductance-voltage curves are derived numerically. WKB fits to the conductance-voltage curves are obtained using a two-component trapezoidal plus square ͑TRAPSQR͒ model barrier potential to determine values for the tunnel barrier parameters ͑height, shape, and width͒; these parameters are consistent with AFM topological measurements and values from similar devices reported in the literature. IET spectra are presented which confirm that electrons tunnel through ultrathin regions of the a-CdTe:O films, which contain aluminum oxide subregions in a manner consistent with the TRAPSQR barrier model. Because tunneling occurs predominantly through these ultrathin regions, IET spectroscopic data obtained are representative of states at, or within a few tenths of nanometers from, the surface and confirm that the a-CdTe:O surface stoichiometry is very sensitive to changes in the argon/oxygen/nitrogen concentration ratios during film growth. Full IET spectra, current-voltage, and conductance-voltage data are presented together with tunnel barrier parameters derived from ͑WKB͒ fits to the data. The results presented here indicate that inelastic electron tunneling spectroscopy is a useful tool for characterizing the surface states of a-CdTe:O and possibly other photovoltaic materials.

show abstract

Inelastic electron tunneling spectroscopy of triethoxysilane on germania: a model study for silane-glass adhesion

Cited by 8 publications

References 13 publications

A Fourier Transform Infrared (FTIR) Study of the Reaction of Triethoxysilane (TES) and Bis[3-triethoxysilylpropyl]tetrasulfane (TESPT) with the Surface of Amorphous Silica

A Fourier Transform Infrared (FTIR) Study of the Reaction of Triethoxysilane (TES) and Bis[3-triethoxysilylpropyl]tetrasulfane (TESPT) with the Surface of Amorphous Silica

Characterization of Metal Oxide Surfaces and Thin Semiconductor Films by Inelastic Electron Tunneling Spectroscopy

Spectroscopic, topological, and electronic characterization of ultrathin a-CdTe:O tunnel barriers

Contact Info

Product

Resources

About