Evidence of Lattice Relaxation in Platinum-Doped Silicon

1985 ◽  
Vol 46 ◽  
Author(s):  
Santos Mayo ◽  
J. R. Lowney ◽  
M. I. Bell
Keyword(s):  
Deep Level ◽  
Photoionization Cross Section ◽  
Lattice Relaxation ◽  
Coupling Model ◽  
Electronic Energy ◽  
Acceptor Level ◽  
Carrier Recombination ◽  
Prism Monochromator ◽  
Phosphorus Levels ◽  
Good Agreement

AbstractThe photoionization cross section of the platinum-acceptor level in silicon was measured (in relative units) as a function of photon energy. Capacitance transients due to electron emission from this level were studied in a p+n gated photodiode at temperatures of 40, 60, and 80 K. Measurements were made over the wavelength range of 2 to 5 μm with light from a prism monochromator with a constant bandpass of 10 meV. The platinum density in the diode was about 1014 cm−3, providing a ratio of deep to shallow (phosphorus) levels of about 0.1. The data are in good agreement with the Ridley-Amato lattice-coupling model when a Huang-Rhys parameter of S = 0.3 is used, corresponding to a Frank-Condon shift of 15 meV if an average phonon energy of 50 meV is assumed. The electronic energy of the acceptor level was 226 ± 5 meV below the conduction band, independent of temperature and in agreement with previous studies of thermal ionization. The present results provide the first clear experimental evidence of lattice relaxation associated with a deep level in silicon. However, the observed Huang-Rhys parameter is smaller than the theoretical estimates of Lowther (S ≅ 1), suggesting that multiphonon emission may not be the only mechanism for carrier recombination involving this level.

Lifetime Regime in the Electrically-Detected Transient Grating Method Applied to Amorphous and Microcrystalline Silicon Films

2002 ◽  
Vol 715 ◽  
Author(s):  
P. Sanguino ◽  
M. Niehus ◽  
S. Koynov ◽  
P. Brogueira ◽  
R. Schwarz ◽  
...  
Keyword(s):  
Carrier Transport ◽  
Analytical Calculation ◽  
Chemical Vapor ◽  
Silicon Films ◽  
Dielectric Relaxation Time ◽  
Transient Grating ◽  
Minority Carrier Diffusion Length ◽  
Carrier Recombination ◽  
Thin Silicon ◽  
Good Agreement

AbstractThe minority-carrier diffusion length in thin silicon films can be extracted from the electrically-detected transient grating method, EDTG, by a simple ambipolar analysis only in the case of lifetime dominated carrier transport. If the dielectric relaxation time, τdiel, is larger than the photocarrier response time, τR, then unexpected negative transient signals can appear in the EDTG result. Thin silicon films deposited by hot-wire chemical vapor deposition (HWCVD) near the amorphous-to-microcrystalline transition, where τR varies over a large range, appeared to be ideal candidates to study the interplay between carrier recombination and dielectric response. By modifying the ambipolar description to allow for a time-dependent carrier grating build-up and decay we can obtain a good agreement between analytical calculation and experimental results.

Recombination of Optically Excited Carriers in a-Si:H at Low temperatures and Intermediate Times

2002 ◽  
Vol 715 ◽  
Author(s):  
J. Whitaker ◽  
T. Su ◽  
P. C. Taylor
Keyword(s):  
Electron Spin Resonance ◽  
Low Temperatures ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Dipolar Relaxation ◽  
Spin Lattice ◽  
Carrier Recombination ◽  
Nmr Data ◽  
Spin Resonance ◽  
Time Regime

AbstractOptically induced electron spin resonance (LESR) studies on time scales in between the previously published PL and LESR results (approximately 10 ms to 10 s) allow one to examine the cross over between energy-loss (downward) hopping of carriers and carrier recombination via tunneling. In addition, data in this time regime are directly compared in the same sample with NMR data on the dipolar spin-lattice relaxation of the bonded hydrogen where light induced electrons and holes are responsible for dipolar relaxation of bonded hydrogen. The LESR results confirm the interpretation of the NMR measurements.

scholarly journals Local and electronic structure around Ga in CdTe: evidence of DX- and A-centers

2012 ◽  
Vol 20 (1) ◽  
pp. 166-171
Author(s):  
Vasil Koteski ◽  
Jelena Belošević-Čavor ◽  
Petro Fochuk ◽  
Heinz-Eberhard Mahnke
Keyword(s):  
Density Functional ◽  
Plane Waves ◽  
Lattice Relaxation ◽  
Defect Structures ◽  
Functional Theory ◽  
Edge Structure ◽  
X Ray ◽  
First Time ◽  
X Ray Absorption ◽  
Good Agreement

The lattice relaxation around Ga in CdTe is investigated by means of extended X-ray absorption spectroscopy (EXAFS) and density functional theory (DFT) calculations using the linear augmented plane waves plus local orbitals (LAPW+lo) method. In addition to the substitutional position, the calculations are performed for DX- and A-centers of Ga in CdTe. The results of the calculations are in good agreement with the experimental data, as obtained from EXAFS and X-ray absorption near-edge structure (XANES). They allow the experimental identification of several defect structures in CdTe. In particular, direct experimental evidence for the existence of DX-centers in CdTe is provided, and for the first time the local bond lengths of this defect are measured directly.

NUCLEAR MAGNETIC RELAXATION IN GAS MIXTURES

1962 ◽  
Vol 40 (8) ◽  
pp. 1027-1035 ◽  
Author(s):  
D. Llewelyn Williams
Keyword(s):  
Room Temperature ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Gas Molecules ◽  
De Broglie Wavelength ◽  
Diffraction Effects ◽  
Good Agreement

Measurements of the proton spin–lattice relaxation time using pulse techniques have been made on the hydrogen–nitrogen, hydrogen–neon, and hydrogen–helium systems from room temperature to 60° K. The results are in good agreement with the Oppenheim–Bloom theory and illustrate the importance of the radial distribution of the gas molecules and of diffraction effects associated with the de Broglie wavelength.

A Discussion on photoelectron spectroscopy - Franck-Condon factors and autoionization in the photoelectron spectra of diatomic molecules

1970 ◽  
Vol 268 (1184) ◽  
pp. 159-162 ◽  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Photoionization Cross Section ◽  
Resonance Wavelength ◽  
Exciting Radiation ◽  
Vibrational Structure ◽  
Photoelectron Spectra ◽  
Condon Factors ◽  
Franck Condon ◽  
Characteristic Manner ◽  
Good Agreement

Distributions of calculated Franck-Condon factors for autoionizing transitions are used to illustrate the way in which the vibrational structure of the photoelectron spectrum may be extended in a characteristic manner when the wavelength of the exciting radiation coincides with a resonance in the photoionization cross section of a diatomic gas. The calculations are found to be in good agreement with resonance wavelength photoelectron spectra from O2.

A133Cs NMR Spin-Lattice Relaxation Study in Incommensurate Cs2CdI4

2000 ◽  
Vol 55 (1-2) ◽  
pp. 339-342 ◽  
Author(s):  
Koh-ichi Suzuki ◽  
Shin'ichi Ishimaru ◽  
Ryuichi Ikeda
Keyword(s):  
Critical Exponent ◽  
Relaxation Times ◽  
Three Dimensional ◽  
Lattice Relaxation ◽  
Normal Phase ◽  
Incommensurate Phase ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Relaxation Study ◽  
Good Agreement

133Cs NMR spin-lattice relaxation times(T1) in crystalline Cs2CdI4 were measured at 225 - 373 K. The critical exponent ( of T\ observed near the normal-incommensurate transition in the normal phase was determined to be 0.62 ± 0.03, in good agreement with the predicted value for three-dimensional XK-model. The frequency dependent T1 in the incommensurate phase could be explained by the fluctuation of amplitudon and small gap phason.

Deep-level wave functions including lattice-relaxation effects

1993 ◽  
Vol 47 (8) ◽  
pp. 4281-4288 ◽  
Author(s):  
Wei-Gang Li ◽  
Charles W. Myles
Keyword(s):  
Deep Level ◽  
Lattice Relaxation ◽  
Wave Functions ◽  
Relaxation Effects

Deep level transient spectroscopic and Hall effect investigation of the position of the vanadium acceptor level in 4H and 6H SiC

1996 ◽  
Vol 68 (14) ◽  
pp. 1963-1965 ◽  
Author(s):  
J. R. Jenny ◽  
J. Skowronski ◽  
W. C. Mitchel ◽  
H. M. Hobgood ◽  
R. C. Glass ◽  
...  
Keyword(s):  
Hall Effect ◽  
Deep Level ◽  
Acceptor Level

13C and 2H spin–lattice relaxation in solid adamantane

1980 ◽  
Vol 58 (7) ◽  
pp. 655-657 ◽  
Author(s):  
Roderick E. Wasylishen ◽  
Brian A. Pettitt
Keyword(s):  
Angular Correlation ◽  
Transition Point ◽  
Relaxation Times ◽  
Proton Nmr ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Nmr Data ◽  
Plastic Phase ◽  
Good Agreement

Spin–lattice relaxation times for the 13C nuclei of adamantane and the 2H nuclei of adamantane-d16 are reported for most of the temperature range of the solid I (plastic) phase, and for the solid II phase just below the transition point. Angular correlation times are shown to be in good agreement with those previously obtained from proton nmr data by Resing.

Theoretical calculation of the low-lying doublet electronic states of the SrF molecule

2014 ◽  
Vol 92 (10) ◽  
pp. 1223-1231 ◽  
Author(s):  
F. Jardali ◽  
M. Korek ◽  
G. Younes
Keyword(s):  
Electronic States ◽  
Electronic Energy ◽  
Harmonic Frequency ◽  
Complete Active Space ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Schrödinger Perturbation ◽  
First Time ◽  
Good Agreement

The potential energy curves of the low-lying doublet electronic states in the representation 2s+1Λ(+/−) of the SrF molecule have been investigated by using the complete active space self-consistent field with multireference configuration interaction and multireference Rayleigh–Schrödinger perturbation theory methods. The harmonic frequency, ωe; the internuclear distance, Re; the dipole moment; and the electronic energy with respect to the ground state, Te, have been calculated for the considered electronic states. The eigenvalues, Ev; the rotational constants, Bv; and the abscissas of the turning points, Rmin and Rmax, have been investigated using the canonical functions approach. The comparison between the values of the present work and those available in the literature for several electronic states shows very good agreement. Nine new electronic states have been investigated here for the first time.

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