Effect of C Impurities in a-Si:H as Measured by Drive-Level Capacitance, Photo Current, and Electron Spin Resonance

1993 ◽  
Vol 297 ◽  
Author(s):  
J. Hautala ◽  
T. Unold ◽  
J.D. Cohen
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Defect Density ◽  
Drive Level ◽  
Level Data ◽  
Definite Effect ◽  
Wide Range ◽  
Spin Resonance ◽  
Defect Densities ◽  
Photo Current

The effect of C impurities in a-Si:H in levels of 0.4 to 2.6 at. % were studied over a wide range of metastable defect densities. Three complimentary experimental techniques [electron spin resonance (ESR), drive-level capacitance (DLC) and photo-current] were employed to track the material's defect density with light soaking and annealing, as well as Urbach energies, midgap absorption and mobility gaps energies as a function of the C content. Our results show C impurities have a definite effect on the initial and saturated defect densities, as well as the midgap absorption and Urbach energies at levels 1 at. % and above. The results indicate that C acts mainly as a center for increased disorder in the material which results in an increase in the bandtail widths, and consequently an increase in intrinsic defects. Comparison to the ESR and drive-level data show an excellent agreement between these two techniques in determining the bulk defect densities in a-Si:H.

Electron spin resonance in As-doped Ge in a wide range of impurity concentration

1972 ◽  
Vol 49 (2) ◽  
pp. 411-421 ◽  
Author(s):  
E. M. Gershenzon ◽  
N. M. Pevin ◽  
M. S. Fogelson
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Impurity Concentration ◽  
Wide Range ◽  
Spin Resonance

scholarly journals Dynamics of field-induced phases in spin-1 antifferomagnetic chains

2014 ◽  
Author(s):  
Χριστίνα Ψαρουδάκη
Keyword(s):  
Magnetic Field ◽  
Electron Spin Resonance ◽  
Theoretical Analysis ◽  
Electron Spin ◽  
Thermal Transport ◽  
Easy Plane ◽  
Xxz Model ◽  
Plane Anisotropy ◽  
Wide Range ◽  
Spin Resonance

This thesis is devoted to the study of a class of antifferomagnetic spin–1 chains with astrong easy plane anisotropy in the presence of magnetic field H. At zero temperature thesystem undergoes two quantum phase transitions at critical fields H1 and H2. Reliableand detailed theoretical analysis is provided on the Electron Spin Resonance (ESR)spectrum, thermodynamics and the thermal transport of the model. The tools at handrange from exact analytical solutions and to numerical simulation techniques. The S = 1antiferromagnet in a magnetic field can be systematically mapped onto an S = 1/2XXZ chain in a longitudinal magnetic field. This effective S = 1/2 description has beenextensively used in order to gain a better physical understanding of the original S = 1chain.For the Electron Spin Resonance spectrum, apart from the theoretical analysis, high-field ESR experimental studies of the compound N iCl2 − 4SC(NH2)2 (abbreviatedas DTN) are presented and found consistent with theoretical predictions. The mostinteresting feature is the experimental signature of the single–ion two–magnon boundstate.Part of this thesis is devoted to the magnetic–field and temperature dependence ofmagnetization and specific heat for the whole field–region and a wide range of temperatures,with special emphasis at the critical behaviour of these quantities at the criticalfields. Finally, the calculation of dynamic correlation functions pertinent to the studyof thermal transport is addressed for the S = 1 model with easy plane anisotropy andthe S = 1/2 XXZ model in the presence of finite magnetic field.

Excitation Intensity Dependence of Light-Induced Electron Spin Resonance in Hydrogenated Amorphous Silicon Films

1998 ◽  
Vol 507 ◽  
Author(s):  
Baojie Yan ◽  
P. C. Taylor
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Second Harmonic ◽  
Excitation Intensity ◽  
Harmonic Detection ◽  
Dispersive Transport ◽  
Wide Range ◽  
Spin Resonance ◽  
Hydrogenated Amorphous ◽  
Kinetics Of

ABSTRACTLight-induced electron spin resonance in a-Si:H films was measured using second harmonic detection over a wide range of excitation intensities. Second harmonic detection results in an undifferentiated absorption lineshape that saturates much less easily with increasing microwave power. The ratio of the spin densities of the broad line to the narrow line is approximately 3 at a generation rate of 1019 cm−3s−1, and this ratio increases only slightly with decreasing excitation intensity. The kinetics of the LESR after the light is turned on or off show dispersive behavior. The dispersive response of the LESR is related to the dispersive transport of carriers at low temperature. A model that assumes a bimolecular recombination fits the experimental results reasonably well.

Electron Spin Resonance Investigations of Rapid Thermal Oxidized Porous Silicon

1992 ◽  
Vol 283 ◽  
Author(s):  
H. Linke ◽  
P. Omling ◽  
B. K. Meyer ◽  
V. Petrova-Koch ◽  
T. Muschik ◽  
...  
Keyword(s):  
Electron Spin Resonance ◽  
Porous Silicon ◽  
Electron Spin ◽  
Nonradiative Recombination ◽  
Minimum Density ◽  
Spin Resonance ◽  
Different Types ◽  
Oxidized Porous Silicon ◽  
Pl Intensity ◽  
Defect Densities

ABSTRACTWe studied the defect properties present in rapid thermal oxidized porous silicon (RTOPS) by Electron Spin Resonance (ESR). Two different types of defects are distinguished, one similar to the ones observed in damaged c-Si, and in a-Si. The second one is probably related to the Pbo center at the Si/SiO2 interface. The minimum density of 1016 cm-3 is observed for the as etched and for the 900°C oxidized samples, but reaches a maximum of 8×1018 cm-3for the 600°C samples. The PL intensity anticorrelates with the defect densities, which shows that nonradiative recombination via defects is a very powerful channel in quenching the PL efficiency.

Electron spin resonance characteristics of humic acids from a wide range of soil types

2005 ◽  
Vol 36 (7) ◽  
pp. 981-990 ◽  
Author(s):  
Akira Watanabe ◽  
Donald B. McPhail ◽  
Nagamitsu Maie ◽  
Shigeki Kawasaki ◽  
Hamish A. Anderson ◽  
...  
Keyword(s):  
Electron Spin Resonance ◽  
Humic Acids ◽  
Electron Spin ◽  
Soil Types ◽  
Wide Range ◽  
Spin Resonance

Electron Spin Resonance and Electronic Conductivity in Moderately Doped n-type Microcrystalline Silicon as a Probe for the Density of Gap States

2002 ◽  
Vol 715 ◽  
Author(s):  
T. Dylla ◽  
R. Carius ◽  
F. Finger
Keyword(s):  
Electron Spin Resonance ◽  
Electron Spin ◽  
Structural Changes ◽  
Defect Density ◽  
Electronic Conductivity ◽  
Intrinsic Defect ◽  
Charge Carrier Density ◽  
Microcrystalline Silicon ◽  
Spin Resonance ◽  
Gap States

AbstractElectron spin resonance accompanied by conductivity measurements in n-type microcrystalline silicon with different doping concentrations and different structure compositions has been applied for the study of the density of gap states and the influence of these states on charge carrier density. We studied doping concentrations close to the defect density where the doping induced Fermi level (EF) shift is determined by compensation of gap states. We found a correlation between the EF shift, the intrinsic defect density and structural changes.

Electron Spin Resonance Studies of Silicon Dioxide Films on Silicon in Integrated Circuits Using Spin Dependent Recombination

1989 ◽  
Vol 159 ◽  
Author(s):  
M. A. Jupina ◽  
P. M. Lenahan
Keyword(s):  
Electron Spin Resonance ◽  
Integrated Circuits ◽  
Electron Spin ◽  
Oxide Semiconductor ◽  
Surface Areas ◽  
Enhanced Sensitivity ◽  
Active Point ◽  
Spin Resonance ◽  
Effect Transistor ◽  
Defect Densities

ABSTRACTThe technique of spin dependent recombination (SDR) allows the electron spin resonance (ESR) observation of electrically-active point defects in a single metal-oxide-semiconductor field-effect transistor (MOSFET) with surface areas of only 10-4 cm2 and Si/Si02 interface point defect densities of ∼1011/cm2. With SDR's enhanced sensitivity, devices with different processing details are explored. Differences in the E' spectra for variations in the oxidation processing are discussed.

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