Chemical modification of near‐surface charge trapping in polymers

1984 ◽  
Vol 55 (5) ◽  
pp. 1332-1338 ◽  
Author(s):  
S. Haridoss ◽  
M. M. Perlman
Keyword(s):  
Chemical Modification ◽  
Surface Charge ◽  
Charge Trapping ◽  
Near Surface

Electronic Impact of Inclusions in Diamond

2009 ◽  
Vol 1203 ◽  
Author(s):  
Erik M. Muller ◽  
John Smedley ◽  
Balaji Raghothamachar ◽  
Mengjia Gaowei ◽  
Jeffrey W. Keister ◽  
...  
Keyword(s):  
Charge Trapping ◽  
Secondary Phase ◽  
Surface Region ◽  
Phase Region ◽  
Electron Trapping ◽  
Near Surface ◽  
X Ray ◽  
Photoconductive Gain ◽  
Single Crystal Diamond ◽  
Topography Data

AbstractX-ray topography data are compared with photodiode responsivity maps to identify potential candidates for electron trapping in high purity, single crystal diamond. X-ray topography data reveal the defects that exist in the diamond material, which are dominated by non-electrically active linear dislocations. However, many diamonds also contain defects configurations (groups of threading dislocations originating from a secondary phase region or inclusion) in the bulk of the wafer which map well to regions of photoconductive gain, indicating that these inclusions are a source of electron trapping which affect the performance of diamond X-ray detectors. It was determined that photoconductive gain is only possible with the combination of an injecting contact and charge trapping in the near surface region. Typical photoconductive gain regions are 0.2 mm across; away from these near-surface inclusions the device yields the expected diode responsivity.

scholarly journals Flax Biomass Conversion via Controlled Oxidation: Facile Tuning of Physicochemical Properties

2020 ◽  
Vol 7 (2) ◽  
pp. 38
Author(s):  
Leila Dehabadi ◽  
Abdalla H. Karoyo ◽  
Majid Soleimani ◽  
Wahab O. Alabi ◽  
Carey J. Simonson ◽  
...  
Keyword(s):  
Chemical Modification ◽  
Pore Structure ◽  
Surface Charge ◽  
Chemical Treatment ◽  
Textural Properties ◽  
Adsorption Properties ◽  
Biomass Composition ◽  
Adsorption Sites ◽  
Modified Forms

The role of chemical modification of pristine linen fiber (LF) on its physicochemical and adsorption properties is reported in this contribution. The surface and textural properties of the pristine LF and its peroxyacetic acid- (PAF) and chlorite-treated (CF) fiber forms were characterized by several complementary methods: spectroscopy (SEM, TEM, FT-IR, and XPS), thermal analysis (DSC and TGA), gas/water adsorption isotherms, and zeta potential (ξ). The results obtained reveal that the surface charge and textural properties (surface area and pore structure) of the LF material was modified upon chemical treatment, as indicated by changes in the biomass composition, morphology, ξ-values, and water/dye uptake properties of the fiber samples. Particularly, the pristine LF sample displays preferential removal efficiency (ER) of methylene blue (MB) dye with ER ~3-fold greater (ER~62%) as compared to the modified materials (CF or PAF; ER~21%), due to the role of surface charge of pectins and lignins present in pristine LF. At higher MB concentration, the relative ER values for LF (~19%) relative to CF or PAF (~16%) reveal the greater role of micropore adsorption sites due to the contributing effect of the textural porosity observed for the modified flax biomass at these conditions. Similar trends occur for the adsorption of water in the liquid vs. vapour phases. The chemical treatment of LF alters the polarity/charge of the surface functional groups, and pore structure properties of the chemically treated fibers, according to the variable hydration properties. The surface and textural properties of LF are altered upon chemical modification, according to the variable adsorption properties with liquid water (l) vs. water vapor (g) due to the role of surface- vs. pore-sites. This study contributes to an understanding of the structure-adsorption properties for pristine and oxidized flax fiber biomass. The chemical conversion of such biomass yields biomaterials with tunable surface and textural properties, as evidenced by the unique adsorption properties observed for pristine LF and its modified forms (CF and PAF). This study addresses knowledge gaps in the field by contributing insight on the relationship between structure and adsorption properties of such LF biomass in its pristine and chemically modified forms.

Apparent Resistivity Calculations for Three Two-dimensional Conductivity Models with Vertical Discontinuities

1971 ◽  
Vol 8 (8) ◽  
pp. 961-966 ◽  
Author(s):  
F. W. Jones
Keyword(s):  
Surface Charge ◽  
Numerical Method ◽  
Surface Structure ◽  
Electromagnetic Induction ◽  
Apparent Resistivity ◽  
Two Dimensional ◽  
Near Surface ◽  
A Value ◽  
Surface Contact ◽  
Conductivity Models

Electromagnetic induction in three two-dimensional models of conductors with two regions of different conductivity is considered. Solutions are obtained for both the H-polarization and E-polarization cases by a numerical method. Apparent resistivity as a function of period is plotted for various locations relative to the surface contact. For the H-polarization case, the apparent resistivity values calculated for points near the surface contact are affected by the varying surface charge on the interface between the regions, and a value different from the expected value is obtained. In the E-polarization case the apparent resistivity curves exhibit a "dip" characteristic when the apparent resistivity is calculated for surface points near a shelf or step structure. In both cases the value of apparent resistivity calculated at or near surface contacts between different conducting regions depends greatly on the sub-surface structure.

Passivation of Si and SiGe/Si Structures with 1-Octadecene Monolayers

2007 ◽  
Vol 131-133 ◽  
pp. 83-88
Author(s):  
I.V. Antonova ◽  
M.B. Gulyaev ◽  
R.A. Soots ◽  
V.A. Seleznev ◽  
V.Ya. Prinz
Keyword(s):  
Electrical Properties ◽  
Surface Charge ◽  
Silicon Surface ◽  
Deposition Time ◽  
High Conductivity ◽  
Illumination Intensity ◽  
Surface Layers ◽  
Near Surface ◽  
Surface Pretreatment ◽  
Layer Deposition

The electrical properties of structures included 1-octadecene (CnH2n, n=18) monolayers deposed onto the oxide-free silicon surface or Si/SiGe/Si layers were analyzed as a function of surface pretreatment (hydrogen- or iodine-terminated silicon surface) and layer deposition regime (thermal- or photo-activated process). Two types of traps (for electrons and holes) were found at the interface between the monolayers and substrate. The density of traps was shown to depend on the, H- or I-termination of the silicon surface, the illumination intensity and deposition time during photo-activated deposition, and the temperature of thermal-activated deposition. The optimal regimes can be chosen for minimization of the surface charge in the structures covered with 1- octadecene monolayers, which provides a high conductivity of thin near-surface layers.

Application of the Lany–Zunger polaron correction for calculating surface charge trapping

2017 ◽  
Vol 29 (39) ◽  
pp. 394001 ◽  
Author(s):  
Meisam Farzalipour Tabriz ◽  
Bálint Aradi ◽  
Thomas Frauenheim ◽  
Peter Deák
Keyword(s):  
Surface Charge ◽  
Charge Trapping

Altering protein surface charge with chemical modification modulates protein–gold nanoparticle aggregation

2010 ◽  
Vol 13 (2) ◽  
pp. 625-636 ◽  
Author(s):  
Jennifer A. Jamison ◽  
Erika L. Bryant ◽  
Shyam B. Kadali ◽  
Michael S. Wong ◽  
Vicki L. Colvin ◽  
...  
Keyword(s):  
Chemical Modification ◽  
Surface Charge ◽  
Gold Nanoparticle ◽  
Protein Surface ◽  
Nanoparticle Aggregation ◽  
Gold Nanoparticle Aggregation

Photoreflectance and X-Ray Photoelectron Spectroscopy in Lt MBE GaAs

1991 ◽  
Vol 241 ◽  
Author(s):  
D. C. Look ◽  
J. E. Hoelscher ◽  
J. T. Grant ◽  
C. E. Stutz ◽  
K. R. Evans ◽  
...  
Keyword(s):  
Surface Charge ◽  
Active Layer ◽  
Photoelectron Spectroscopy ◽  
Binding Energies ◽  
Near Surface ◽  
X Ray ◽  
Molecular Beam Epitaxial ◽  
Layer Interface ◽  
Hall Effect Measurements ◽  
Good Agreement

ABSTRACTIt has recently been shown that a 1000Å cap layer of molecular beam epitaxial (MBE) GaAs grown at 200°C passivates the surface of a GaAs active layer (n≃2×1017cm−3) in the sense of reducing the free–carrier depletion which arises from surface acceptor states. The same phenomenon holds for active-layer concentrations up to 7×1018cm−3, for caps as thin as 14Å, and for either As2 or As4 anion species. In an attempt to understand these effects, we have applied photoreflectance (PR) and x–ray photoelectron spectroscopy (XPS). In general, the PR shows contributions from the surface, cap/active–layer interface, and active–layer/buffer–layer interface, because each of these regions can have a different electric field. In fact the various field strengths can be determined from Franz–Keldysh oscillations (FKO), and good agreement with Hall–effect measurements is usually found. However, for 200°C material, no PR is seen, suggesting that there is no surface charge (no surface acceptor states below the Fermi level) or at least no surface–charge modulation by the light. The XPS data, which arise only from the near–surface (∼30Å) region, show that the binding energies in the capped samples are increased (i.e., surface Fermi pinning energy decreased) by 0.2 eV with respect to those in the uncapped samples. These data are discussed in relation to a passivation model.

Effect of surface charge trapping on dielectric barrier discharge

2008 ◽  
Vol 92 (3) ◽  
pp. 031503 ◽  
Author(s):  
Ming Li ◽  
Chengrong Li ◽  
Huamao Zhan ◽  
Jinbao Xu ◽  
Xinxin Wang
Keyword(s):  
Surface Charge ◽  
Dielectric Barrier Discharge ◽  
Barrier Discharge ◽  
Charge Trapping ◽  
Dielectric Barrier ◽  
Effect Of Surface
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