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Charging Effect (charging + effect)

Distribution by Scientific Domains
Chemistry75%

Selected Abstracts

Quantized Double-Layer Charging of Iron Oxide Nanoparticles on a-Si:H Controlled by Charged Defects in a-Si:H

ELECTROANALYSIS, Issue 12 2007
Martin Weis
Abstract Sequential single-electron charging of iron oxide nanoparticles encapsulated in oleic acid/oleyl amine envelope and deposited by the Langmuir-Blodgett technique onto Pt electrode covered with undoped hydrogenated amorphous silicon film (a-Si:H) is reported. Quantized double-layer charging of nanoparticles is detected by cyclic voltammetry as current peaks and the charging effect can be switched on/off by the excess of negative/positive charged defect states in the a-Si:H layer. The particular charge states in a-Si:H are created by the simultaneous application of a suitable bias voltage and illumination before the measurement. [source]

Magnetic field induced charging effect in a single CdSe quantum dot

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 4 2009
Qijun Ren
Abstract We report the magneto-photoluminescence spectroscopy measurements on single CdSe/ZnSe self-assembled QDs. The evolution of the single dot excitonic transition lines exhibits an abnormal energy shift which deviates from the diamagnetic shift and linewidth broadening under magnetic field, followed by the photoluminescence quench at a certain magnetic field. A model involving electron cyclotron motion and tunneling processes is proposed to interpret these novel phenomena and is verified by the coincidence of the large energy shift and the linewidth broadening. This mechanism could be an effective way of external control of charges and optical properties of single QDs. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Gold coating of non-conductive membranes before matrix-assisted laser desorption/ionization tandem mass spectrometric analysis prevents charging effect

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 5 2005
Alexander Scherl
Acquisition of tandem mass spectra from peptides or other analytes deposited on non-conductive membranes is inhibited on instruments combining matrix-assisted laser desorption/ionization with tandem time-of-flight analyzers (MALDI-TOF/TOFÔ) due to a charging effect. A thin layer of gold renders the membrane conductive. This allows adequate data acquisition on MALDI-TOF/TOFÔ systems. Therefore, this methodology extends the capacity of the molecular scanner concept to tandem mass spectrometry. Copyright © 2005 John Wiley & Sons, Ltd. [source]