Scattering and Absorption of Infrared Light on EL2 Clusters in GaAs Semi-Insulating Materials

1986 ◽  
Vol 69 ◽  
Author(s):  
J. P. Fillard ◽  
M. Castagne ◽  
J. Bonnafe ◽  
P. Gall
Keyword(s):  
Low Temperature ◽  
Optical Absorption ◽  
Infrared Light ◽  
Absorption Process ◽  
Infrared Transmission ◽  
Optical Contrast ◽  
Insulating Materials ◽  
Cell Patterns ◽  
Typical Cell ◽  
Center Density

AbstractIt is known that dislocations and EL2 clusters participate in infrared transmission images. Optical quenching of the typical cell patterns at low temperature also charge EL2 with contributing to images. A point yet is not clearly established: such optical contrast could originate in a quantum absorption process or as well in a scattering of the photons. This paper aims at showing that both optical processes are likely to occur in most of the GaAs SI samples and that the two phenomenons can be considered as localy correlated. So monitoring EL2 center density by optical “absorption” could be a trap for the unwarry.

Article

1998 ◽  
Vol 76 (4) ◽  
pp. 411-413
Author(s):  
Yixing Zhao ◽  
Gordon R Freeman
Keyword(s):  
Absorption Spectrum ◽  
Optical Absorption ◽  
Temperature Dependence ◽  
Optical Absorption Spectrum ◽  
Infrared Light ◽  
Solvated Electron ◽  
Solvated Electrons ◽  
Tert Butanol ◽  
Solvent Dependence ◽  
Increasing Temperature

The energy and asymmetry of the optical absorption spectrum of solvated electrons, es- , change in a nonlinear fashion on changing the solvent through the series HOH, CH3OH, CH3CH3OH, (CH3)2CHOH, (CH3)3COH. The ultimate, quantum-statistical mechanical, interpretation of solvated electron spectra is needed to describe the solvent dependence. The previously reported optical spectrum of es- in tert-butanol was somewhat inaccurate, due to a small amount of water in the alcohol and to limitations of the infrared light detector. The present note records the remeasured spectrum and its temperature dependence. The value of the energy at the absorption maximum (EAmax) is 155 zJ (0.97 eV) at 299 K and 112 zJ (0.70 eV) at 338 K; the corresponding values of G epsilon max (10-22 m2 aJ-1) are 1.06 and 0.74. These unusually large changes are attributed to the abnormally rapid decrease of dielectric permittivity of tert-butanol with increasing temperature. The band asymmetry at 299 K is Wb/Wr = 1.8.Key words: optical absorption spectrum, solvated electron, solvent effects, tert-butanol, temperature dependence.

Low Temperature Optical Absorption by Magnons in KNiF3 and NiO Single-Crystals

2000 ◽  
pp. 155-160 ◽  
Author(s):  
N. Mironova ◽  
V. Skvortsova ◽  
A. Kuzmin ◽  
I. Sildos ◽  
N. Zazubovich
Keyword(s):  
Low Temperature ◽  
Optical Absorption ◽  
Single Crystals

Cross-linked poly(hydroxy imide) gate-insulating materials for low-temperature processing of organic thin-film transistors

2018 ◽  
Vol 6 (48) ◽  
pp. 13359-13366 ◽  
Author(s):  
Joo-Young Kim ◽  
Ji Whan Kim ◽  
Eun Kyung Lee ◽  
Jeong-Il Park ◽  
Bang-Lin Lee ◽  
...  
Keyword(s):  
Thin Film ◽  
Low Temperature ◽  
Breakdown Voltage ◽  
Thin Film Transistors ◽  
Organic Thin Film Transistors ◽  
Organic Thin Film ◽  
Insulating Materials ◽  
Plastic Substrates ◽  
Insulating Material ◽  
Low Temperature Processing

This paper reports a polymeric gate insulating material of poly(hydroxy imide) cured at the low temperature of 130 °C for the application to organic thin-film transistors on plastic substrates exhibiting high breakdown voltage and no hysteresis.

Paramagnetic resonance and optical absorption of trapped holes and electrons in irradiated KCI: Ag

1963 ◽  
Vol 271 (1345) ◽  
pp. 243-267 ◽  
Keyword(s):  
Electron Spin Resonance ◽  
Low Temperature ◽  
Optical Absorption ◽  
Electron Spin ◽  
Optical Absorption Spectra ◽  
Paramagnetic Resonance ◽  
Spin Resonance ◽  
Impurity Ions ◽  
Temperature Irradiation ◽  
Positive Holes

The electron spin resonance and optical absorption spectra of crystals of KCl containing silver impurity ions were examined after the crystals had been X -irradiated at 77 °K. It is shown that the silver impurity ions act as traps for both electrons and positive holes. A description is given of the annealing behaviour of the crystals after low-temperature irradiation.

Metastable Percolation Phase Formation in Lif Implanted with Alkali Ions

1981 ◽  
Vol 7 ◽  
Author(s):  
J. Davenas ◽  
P. Thevenard ◽  
C. Dupuy
Keyword(s):  
Low Temperature ◽  
Optical Absorption ◽  
Phase Formation ◽  
Room Temperature ◽  
Critical Concentration ◽  
External Perturbation ◽  
Metallic Layer ◽  
Alkali Ions ◽  
Conducting State ◽  
Equilibrium Situation

ABSTRACTThe formation of a continuous metallic layer in the doped region of LiF crystals implanted at low temperature, has been explained by the formation of bridges between next neighbouring alkali ions of the lattice around-each implanted ion. For a critical concentration of implanted ions it is possible to show using statistical arguments that conducting chains are formed by the union of these links, according to a percolation mechanism. We show that the assumption of a distribution of isolated implanted ions at low temperature is justified by the observation of their precipitation when the crystal is warmed up to room temperature. The transformation of the metallic optical absorption into the colloidal band associated with precipitates of implanted ions is correlated with the transition from a conducting state to an insulating state of the implanted layer. We show that this evolution towards an equilibrium situation may be reversed by a reirradiation, which is used as an external perturbation and that the conducting state associated with dispersed implanted ions is then once again obtained.

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