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

Semiempirical formalism for the calculation of deep-level wave functions inkspace

1986 ◽  
Vol 33 (12) ◽  
pp. 8234-8237 ◽  
Author(s):  
H-H. Dai ◽  
M. A. Gundersen ◽  
Charles W. Myles
Keyword(s):  
Deep Level ◽  
Wave Functions

Lattice Relaxation Effects in Si and GaAs Nanocrystals

1994 ◽  
Vol 358 ◽  
Author(s):  
X. S. Zhao ◽  
Y. R. Ge ◽  
J. Schroeder ◽  
P. D. Persans
Keyword(s):  
Gallium Arsenide ◽  
Optical Properties ◽  
Porous Silicon ◽  
Raman Scattering ◽  
Lattice Relaxation ◽  
Experimental Results ◽  
Vibrational Modes ◽  
Strain Effects ◽  
Relaxation Effects ◽  
Almost All

ABSTRACTRaman scattering results on porous silicon, and silicon and gallium arsenide nanocrystals show that almost all vibrational modes become Raman active and remarkably soft in these nanocrystal systems. The experimental results further demonstrate that the carrier-induced strain effects play an important role on the optical properties of such nanocrystal systems.

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.

OPTICAL FARADAY ROTATION STUDIES OF PARAMAGNETIC RESONANCE IN NEODYMIUM ETHYLSULPHATE

1963 ◽  
Vol 41 (1) ◽  
pp. 33-45 ◽  
Author(s):  
K. E. Rieckhoff ◽  
D. J. Griffiths
Keyword(s):  
Steady State ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Spin Interaction ◽  
Spatial Gradient ◽  
Constant Field ◽  
Paramagnetic Resonance ◽  
Spin Lattice ◽  
Relaxation Effects

The magneto-optical Faraday effect was used to measure the saturation of the spin levels in concentrated neodymium ethylsulphate in both steady-state and pulsed microwave resonance experiments at liquid helium temperatures. The steady-state experiments yielded the paramagnetic resonance spectrum consisting of a main triplet and an extensive hyperfine structure. The line positions are explained in terms of the known spin Hamiltonian of the diluted salt and spin–spin interaction between nearest neighbors. An asymmetry of the line shape was observed for sufficiently low temperatures in qualitative agreement with existing theories. Measurements of saturation s versus microwave power P at constant field and temperature were made and yielded the relationship [Formula: see text] for s > 10%. The steady-state experiments also revealed the existence of a spatial gradient in the saturation across the sample.The pulsed experiments gave the spin–lattice relaxation time τ as a function of magnetic field H at various temperatures. At 4.2 °K, τ was found to be independent of H and of the order of 11 msec for fields from 800 to [Formula: see text], while at temperatures below 2 °K, τ was found to be strongly field-dependent, indicating the importance of cross-relaxation effects at temperatures [Formula: see text].

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