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Interface States (interface + states)
Selected AbstractsTransient scattering of plane waves from an inclusion with a unilateral frictional contact interface,a 2D time domain boundary element analysisINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 4 2004Yang-De Feng Abstract This paper is the continuity of our previous work (Commun Numer Meth Engng 2003; 19: 25,36) which applies the 2D time domain boundary element method (BEM) to solve the transient scattering of SH waves by an inclusion with a unilateral frictional contact interface. The case of the plane wave (P and/or SV wave) incidence is studied. Localized slip and separation at the interface caused by strong incident waves are considered. Therefore the interface involves three different kinds of unknown intervals: slip, separation and stick regions. In order to determine the unknown intervals, an iterative technique is developed. As an example, we compute the scattering of P waves by a cylinder of circular cross-section embedded in an infinite solid. Numerical results for the near field solutions are presented. The distortion of the response waves and the variation of the interface states are discussed. Copyright © 2004 John Wiley & Sons, Ltd. [source] Time-resolved two-photon photoemission at metal,dielectric interfacesISRAEL JOURNAL OF CHEMISTRY, Issue 1-2 2005Wolfram Berthold We review the influence of rare-gas layers on image-potential states at metal surfaces. Experiments on Xe, Kr, and Ar on Cu(100) and on Xe/Ru(0001) that use the technique of time-resolved two-photon photoemission are discussed. The energetic position of the electron affinity, the geometry of the adsorbate layer, and dielectric screening are the factors that influence the dynamical and energetic properties of the states. Theories on various levels are compared, including 1- and 3-dimensional models and the GW approximation of many-body theory. We also present new results on buried interface states that exist in the band gaps of both the Cu(100) substrate and a thick adsorbed Ar layer. [source] Electrical characteristics of Al/polyindole Schottky barrier diodes.JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2009Abstract In this study, the forward and reverse bias current,voltage (I,V), capacitance,voltage (C,V), and conductance,voltage (G/,,V) characteristics of Al/polyindole (Al/PIN) Schottky barrier diodes (SBDs) were studied over a wide temperature range of 140,400 K. Zero-bias barrier height ,B0(I,V), ideality factor (n), ac electrical conductivity (,ac), and activation energy (Ea), determined by using thermionic emission (TE) theory, were shown fairly large temperature dispersion especially at lower temperatures due to surface states and series resistance of Al/PIN SBD. I,V characteristics of the Al/PIN SBDs showed an almost rectification behavior, but the reverse bias saturation current (I0) and n were observed to be high. This high value of n has been attributed to the particular distribution of barrier heights due to barrier height inhomogeneities and interface states that present at the Al/PIN interface. The conductivity data obtained from G/,V measurements over a wide temperature range were fitted to the Arrhenius and Mott equations and observed linear behaviors for ,ac vs. 1/T and ln ,ac vs. 1/T1/4 graphs, respectively. The Mott parameters of T0 and K0 values were determined from the slope and intercept of the straight line as 3.8 × 107 and 1.08 × 107 Scm,1K1/2, respectively. Assuming a value of 6 × 1012 s,1 for ,0, the decay length ,,1 and the density states at the Fermi energy level, N(EF) are estimated to be 8.74 Å and 1.27 × 1020 eV,1cm,3, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Low- and high-frequency C,V characteristics of the contacts formed by sublimation of the nonpolymeric organic compound on p-type Si substratePHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 14 2004C. Temirci Abstract The Sn/pyronine- B/p-Si Schottky structures have been obtained by sublimation of the organic compound pyronine- B onto the top of a p-Si surface. Barrier height and ideality factor value of 0.79 eV and 1.13, respectively, for the device have been determined from the forward-bias current,voltage (I,V) characteristics. The interface state density obtained from the forward bias high and low capacitance,voltage characteristics increases exponentially with bias between the midgap and the top of the valance band, from 2.15 × 1010 cm,2 eV,1 at (0.79,Ev) eV to 1.16 × 1012 cm,2 eV,1 at (0.53,Ev) eV. These values have been compared to those of the metal/Si structures in the literature, and it is seen that the presence of the nonreactive organic materials at the inorganic semiconductor and metal interface may obstruct the generation of the interface states at the semiconductor surface that strongly influence the Schottky barrier formation. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Intermolecular band dispersion in highly ordered monolayer and multilayer films of pentacene on Cu(110)PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 5 2008Hiroyuki Yamane Abstract We report the electronic structure and the charge transport mechanism of highly ordered films of pentacene on Cu(110) surface studied by angle-resolved ultraviolet photoemission spectroscopy using synchrotron radiation. For a flat-lying monolayer film, we observed the evidences of (i) formation of the interface states and (ii) two-dimensional intermolecular band dispersion of the resultant interface states, which may originate from the hybridization between the molecular orbi-tals and the wave function of the substrate. For an upright-standing multilayer film, we observed the two-dimensional intermolecular band dispersion, which originates from the intermolecular ,,, interaction. The observed effective masses of the hole for different azimuths demonstrate the presence of the anisotropy of the hole mobility in pentacene crystals also at higher temperatures. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Shallow- and deep-luminescence centers in AgI-based superionic conductor glassPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 2 2003Shosuke Mochizuki Abstract The photoluminescence (PL), time-resolved photoluminescence (TRPL) and PL-excitation (PLE) spectra of superionic conductor glass (AgI)0.85(Ag2WO4)0.15 have been measured at different temperatures between 8 K and room temperature. The PL intensity peak is observed at 426 nm which corresponds to free exciton wavelength of pristine AgI. There are also different PL bands well related to the internal and interface states of mesoscopic AgI particles in Ag2WO4 glass matrix. This may give important information about the origins of superionic conduction. With increasing excitation light intensity, the PL efficiencies of several emission bands become saturated, except for the free exciton band. [source] Growth of Hafnium Aluminate Thin Films by Liquid Injection MOCVD Using Alkoxide Precursors,CHEMICAL VAPOR DEPOSITION, Issue 5 2004P.A. Marshall Abstract Thin films of Hf aluminate, (HfO2)x(Al2O3)1,x (Al,=,8.4,38.5,at.-%) have been deposited by liquid injection MOCVD using the metal alkoxide precursors [Hf(mmp)4] (mmp,=,OCMe2CH2OMe) and [Al(OiPr)3]. (HfO2)x(Al2O3)1,x thin films deposited at 500,°C had a thickness range of 7,13,nm and were high purity, with no carbon detected by Auger electron spectroscopy (AES) at the estimated detection limit of 0.5,at.-%. Thick films of (HfO2)x(Al2O3)1,x containing more than ,7,at.-% Al were found by X-ray diffraction (XRD) to be amorphous. High frequency capacitance,voltage (C,V) measurements indicate strong electron trapping and a high density of interface states. [source] | |||||||||||||