On the Origin of EL2 Intracenter Absorption Band in GaAs

1987 ◽  
Vol 104 ◽  
Author(s):  
M. Skowronski
Keyword(s):  
Absorption Band ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Conduction Band ◽  
Metastable State ◽  
Uniaxial Stress ◽  
Alternative Interpretation ◽  
Optical Absorption Spectra ◽  
Wide Absorption Band ◽  
Dx Center

ABSTRACTAn alternative interpretation of optical absorption spectra due to intracenter transition within EL2 defect in GaAs is provided. The arguments are presented that states originating from the L-valley of the conduction band can account for the presence of the wide absorption band, the no-phonon line and the observed uniaxial stress splittings. Using the analogy to the DX center, this model presents an explanation for the existence of the metastable state of EL2.

A photoconductivity study of trapped electrons in γ-irradiated hydrocarbon glasses at 77 K

1983 ◽  
Vol 61 (12) ◽  
pp. 2799-2803 ◽  
Author(s):  
Naoto Okabe ◽  
Toyoaki Kimura ◽  
Kenji Fueki
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Conduction Band ◽  
Ground State ◽  
Volume Ratio ◽  
Optical Absorption Spectra ◽  
Trapped Electrons ◽  
Trapped Electron

Photoconductivity spectra of trapped electrons in γ-irradiated 3-methylpentane, 2-methylpentane, 3-methylheptane, and 3-methylpentane–methylcyclohexane (1:9 volume ratio) glasses at 77 K were measured. From the comparison of photoconductivity and optical absorption spectra in these systems we have obtained relative values of quantum efficiencies for a trapped electron in the ground state to be excited to the conduction band by photo-induced transition. For electrons stably trapped, we have measured the ranges of trap depths from the shallowest to the deepest in these systems.

Optical Absorption Spectra Under DC Light Bias in Undoped a-Si:H

1992 ◽  
Vol 258 ◽  
Author(s):  
J. Z. Liu ◽  
J. P. Conde ◽  
G. Lewen ◽  
P. Roca i Cabarrocas
Keyword(s):  
Simple Model ◽  
Absorption Band ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Optical Absorption Spectra ◽  
Recombination Lifetime ◽  
Photothermal Deflection Spectroscopy ◽  
Photothermal Deflection

ABSTRACTUnder a dc light bias, the ac constant photocurrent method (CPM) yields an anomalous subgap optical absorption over that without the bias. When the intensity of the bias is high, an absorption band appears. However, absorption measured by ac photothermal deflection spectroscopy (PDS) is much less affected by the bias. A simple model qualitatively explains the effect on the PDS spectra and suggests that the anomalous CPM absorption is an apparent one which represents a variation of the recombination lifetime.

scholarly journals Fast optical absorption spectra calculations for periodic solid state systems

2020 ◽  
Vol 15 (1) ◽  
pp. 89-113
Author(s):  
Felix Henneke ◽  
Lin Lin ◽  
Christian Vorwerk ◽  
Claudia Draxl ◽  
Rupert Klein ◽  
...  
Keyword(s):  
Solid State ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Optical Absorption Spectra

NIR and Upconversion Luminescence Properties of Nd3+ Doped in Gd2O3-CaO-SiO2-B2O3 Glass System

2014 ◽  
Vol 548-549 ◽  
pp. 124-128 ◽  
Author(s):  
S. Insiripong ◽  
S. Kaewjeang ◽  
U. Maghanemi ◽  
H.J. Kim ◽  
N. Chanthima ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Upconversion Luminescence ◽  
Emission Spectra ◽  
Concentration Quenching ◽  
Luminescence Spectra ◽  
Optical Absorption Spectra ◽  
Glass Matrices ◽  
Nir Luminescence

In this work, properties of Nd3+ in Gd2O3-CaO-SiO2-B2O3 glass systems with composition 25Gd2O3-10CaO-10SiO2-(55-x)B2O3-xNd2O3 where x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol% were investigated. The optical absorption spectra show peaks at 4F3/2 (877 nm) , 4F5/2+2H9/2 (802 nm), 4F7/2+4S3/2 (743 nm), 4F9/2 (682 nm), 2H11/2 (627 nm), 2G7/2 +4G5/2 (582 nm), 4G7/2 +2K13/2 (527 nm), 4G11/2 (481 nm), 2P1/2 (427 nm) and 2L15/2 + 4D1/2 + 1I11/2+ 4D5/2+ 4D3/2 (355 nm) reflecting the Nd3+ ions in glass matrices. The densities were increased with increasing of Nd2O3 concentration. This indicates the increase of the molecular weight by the replacement of B2O3 with a heavier Nd2O3 oxide in the glass. The upconversion luminescence spectra show bands at 393 nm for all Nd2O3 concentration and the strongest intensity from 2.5 % mol of Nd2O3 was obtained. For NIR luminescence, the intensity of Nd3+ emission spectra increases with increasing concentrations of Nd3+ up to 1.5 mol% and beyond 1.5 mol% the concentration quenching is observed.

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