ESR Study of Electron States in Ge/Si Heterostructures with Nanodisc Shaped Quantum Dots

2017 ◽  
Vol 231 (2) ◽  
Author(s):  
Aigul F. Zinovieva ◽  
Vladimir A. Zinovyev ◽  
Alexey V. Nenashev ◽  
Leonid V. Kulik ◽  
Anatoly V. Dvurechenskii
Keyword(s):  
Quantum Dots ◽  
Electron Spin Resonance ◽  
Coulomb Interaction ◽  
Electron Spin ◽  
Esr Spectra ◽  
Light Illumination ◽  
Electron States ◽  
The Third ◽  
Signal Assignment ◽  
Spin Resonance

AbstractElectron states in Ge/Si heterostructures with nanodisc shaped quantum dots (QDs) were studied using the electron spin resonance (ESR) method. Three ESR signals were observed under light illumination of the samples. The analysis of the angular dependences of the ESR spectra allows one performing signal assignment. Two ESR signals observed in the dark, as well as under illumination, are related to the electrons localized due to the strain at the top edges and base edges of the nanodiscs, while the third ESR signal observed only under illumination is related to the electrons localized in the Si layer above (or under) the central parts of the nanodiscs due to the Coulomb interaction with photoholes. A comparison with ESR results obtained for structures with lens-shaped QDs was performed. It was found that the nanodisc shape is crucial for the simultaneous localization of three electrons with different

Electron-spin-resonance meanderlines for effective spin control in Si quantum dots for large-scale qubit applications

2021 ◽  
Vol 119 (24) ◽  
pp. 243503
Author(s):  
Yao-Chun Chang ◽  
Ian Huang ◽  
Chiung-Yu Chen ◽  
Min-Jui Lin ◽  
Shih-Yuan Chen ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electron Spin Resonance ◽  
Electron Spin ◽  
Large Scale ◽  
Effective Spin ◽  
Spin Resonance ◽  
Si Quantum Dots

Electron Spin Resonance in Heterostructures with Ring Molecules of GeSi Quantum Dots

JETP Letters ◽  
2021 ◽  
Vol 113 (1) ◽  
pp. 52-56
Author(s):  
A. F. Zinovieva ◽  
V. A. Zinovyev ◽  
A. V. Nenashev ◽  
A. A. Shklyaev ◽  
L. V. Kulik ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electron Spin Resonance ◽  
Electron Spin ◽  
Ring Molecules ◽  
Spin Resonance

FREE RADICALS OF BIOLOGICAL INTEREST: PART II. ELECTRON SPIN RESONANCE (ESR) SPECTRA OF 2537 A IRRADIATED AMINO ACIDS

1967 ◽  
Vol 45 (12) ◽  
pp. 1831-1839 ◽  
Author(s):  
W. F. Forbes ◽  
P. D. Sullivan
Keyword(s):  
Amino Acids ◽  
Electron Spin Resonance ◽  
Electron Spin ◽  
Hydrogen Abstraction ◽  
Esr Spectra ◽  
Side Chain ◽  
Biological Interest ◽  
Spin Resonance ◽  
Cyclohexadienyl Radical ◽  
Secondary Radical

Polycrystalline amino acids, when irradiated with 2537 Å light, afford a variety of electron spin resonance signals. These signals are generally stable at room temperature for relatively long periods of time. For a number of the spectra obtained, there is evidence that more than one radical species contributes to the observed spectra. The signals obtained frequently differ from those obtained on exposure to ionizing radiation. The postulated species formed can often be visualized as being formed by effective hydrogen abstraction from the alkyl-substituted tertiary carbon atom or from the —OH, —SH or —NH group contained in the side chain. For L-phenylalanine a secondary radical is obtained, which is ascribed to a cyclohexadienyl radical.

Electron spin resonance in double quantum dots

2008 ◽  
Vol 40 (5) ◽  
pp. 1457-1459 ◽  
Author(s):  
Rafael Sánchez ◽  
Carlos López-Monís ◽  
Jesús Iñarrea ◽  
Gloria Platero
Keyword(s):  
Quantum Dots ◽  
Electron Spin Resonance ◽  
Electron Spin ◽  
Double Quantum ◽  
Double Quantum Dots ◽  
Spin Resonance

Electron spin resonance observations of photochemically generated contact ammonium ion-pairs of fluoro-substituted ketones

1979 ◽  
Vol 57 (5) ◽  
pp. 600-602 ◽  
Author(s):  
K. S. Chen ◽  
T. Foster ◽  
J. K. S. Wan
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Ion Pairs ◽  
Esr Spectra ◽  
Ammonium Ion ◽  
Spin Resonance ◽  
Photochemical Systems

Contact radical ion-pairs of ammonium and fluoro-substituted ketones were generated in photochemical systems and their here-to-fore elusive esr spectra were characterized.

Electronic Properties of Polymer-Fullerene Solar Cells

2001 ◽  
Vol 665 ◽  
Author(s):  
V. Dyakonov ◽  
I. Riedel ◽  
C. Deibel ◽  
J. Parisi ◽  
C. J. Brabec ◽  
...  
Keyword(s):  
Solar Cells ◽  
Electron Spin Resonance ◽  
Electron Spin ◽  
Fill Factor ◽  
Short Circuit ◽  
Open Circuit ◽  
Light Illumination ◽  
Positive Temperature ◽  
Admittance Spectroscopy ◽  
Spin Resonance

ABSTRACTWe studied the electronic transport properties of conjugated polymer/fullerene based solar cells by means of temperature and illumination intensity dependent current-voltage characteristics, admittance spectroscopy and light-induced electron spin resonance. The short-circuit current density increases with temperature at all light illumination intensities applied, i.e., from 100 mW/cm2 to 0.1 mW/cm2 (white light), whereas a temperature independent behavior was expected. An increase of the open-circuit voltage from 850 mV to 940 mV was observed, when cooling down the device from room temperature to 100 K. The fill factor depends strongly on temperature with a positive temperature coefficient in the whole temperature range. In contrast, the light intensity dependence of the fill factor shows a maximum of 52% at intermediate illumination intensities (3 mW/cm2) and decreases subsequently, when increasing the intensity up to 100 mW/cm2. Further studies by admittance spectroscopy revealed two frequency dependent contributions to the device capacitance. One, as we believe, originates from trapping states located at the interface between composite and metal electrode with an activation energy of EA=180 meV, and the other one is from very shallow bulk states with EA=10 meV. The origin of the latter is possibly the thermally activated conductivity. The photo-generation of charge carriers and their fate in these blends have been studied by light-induced electron spin resonance. We can clearly distinguish between photo-generated electrons and holes in the composites due to different spectroscopic splitting factors (g-factors). Additional information on the environmental axial symmetry of the holes located on the polymer chains as well as on a lower, rhombic, symmetry of the electrons located on the methanofullerene molecules has been obtained. The origin of the signals and parameters of the g-tensor have been confirmed from studies on a hole doped polymer.

Electron Spin Resonance Investigations on Perovskite Solar Cell Materials Deposited on Glass Substrate

MRS Advances ◽  
2018 ◽  
Vol 3 (32) ◽  
pp. 1831-1836
Author(s):  
C. L. Saiz ◽  
E. Castro ◽  
L. M. Martinez ◽  
S. R. J. Hennadige ◽  
L. Echegoyen ◽  
...  
Keyword(s):  
Electron Spin Resonance ◽  
Solar Cell ◽  
Line Width ◽  
Electron Spin ◽  
Glass Substrate ◽  
Esr Spectra ◽  
Perovskite Solar Cell ◽  
Hole Transport ◽  
Ex Situ ◽  
Spin Resonance

ABSRTACTIn this article, we report low-temperature electron spin resonance (ESR) investigations carried out on solution processed three-layer inverted solar cell structures: PC61BM/CH3NH3PbI3/PEDOT:PSS/Glass, where PC61BM and PEDOT:PSS act as electron and hole transport layers, respectively. ESR measurements were conducted on ex-situ light (1 Sun) illuminated samples. We find two distinct ESR spectra. First ESR spectra resembles a typical powder pattern, associated with gx = gy = 4.2; gz = 9.2, found to be originated from Fe3+ extrinsic impurity located in the glass substrate. Second ESR spectra contains a broad (peak-to-peak line width ∼ 10 G) and intense ESR signal appearing at g = 2.008; and a weak, partly overlapped, but much narrower (peak-to-peak line width ∼ 4 G) ESR signal at g = 2.0022. Both sets of ESR spectra degrade in intensity upon light illumination. The latter two signals were found to stem from light-induced silicon dangling bonds and oxygen vacancies, respectively. Our controlled measurements confirm that these centers were generated during UV-ozone treatment of the glass substrate –a necessary step to be performed before PEDOT:PSS is spin coated. This work forms a significant step in understanding the light-induced- as well as extrinsic defects in perovskite solar cell materials.

Microscopic Study of Metal Hydrides using Electron Spin resonance

1980 ◽  
Vol 3 ◽  
Author(s):  
E. L. Venturini
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Metal Hydrides ◽  
Esr Spectra ◽  
Spectroscopic Technique ◽  
Host Lattice ◽  
Hydrogen Ions ◽  
Spin Resonance ◽  
Symmetry Phase ◽  
Paramagnetic Ions

ABSTRACTElectron spin resonance (ESR) of dilute paramagnetic ions in nonmagnetic metallic hydrides provides microscopic information about the hydrogen ions in the immediate vicinity of the impurity. By comparing ESR spectra for different host metals and several hydrogen/metal ratios, one can determine material properties including host lattice symmetry, phase boundaries and occupation of available sites by hydrogen. Examples are presented of ESR of dilute Er in group IIIB and IVB metal hydrides, demonstrating the sensitivity and versatility of ESR as a spectroscopic technique.

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