The Role of Oxide Traps Aligned With the Semiconductor Energy Gap in MOS Systems

2020 ◽  
Vol 67 (10) ◽  
pp. 4372-4378 ◽  
Author(s):  
Enrico Caruso ◽  
Jun Lin ◽  
Scott Monaghan ◽  
Karim Cherkaoui ◽  
Farzan Gity ◽  
...  
Keyword(s):  
Energy Gap ◽  
Oxide Traps

The Role of Rare Earths in Narrow Energy Gap Semiconductors

1990 ◽  
Vol 216 ◽  
Author(s):  
D.L. Partin ◽  
J. Heremans ◽  
D.T. Morelli ◽  
C.M. Thrush
Keyword(s):  
Rare Earth ◽  
Band Gap ◽  
Indium Antimonide ◽  
Energy Band ◽  
Energy Gap ◽  
Lattice Parameter ◽  
Molecular Beam Epitaxy Growth ◽  
Lead Chalcogenide ◽  
Energy Band Gap

ABSTRACTNarrow energy band gap semiconductors are potentially useful for various devices, including infrared detectors and diode lasers. Rare earth elements have been introduced into lead chalcogenide semiconductors using the molecular beam epitaxy growth process. Europium and ytterbium increase the energy band gap, and nearly lattice-matched heterojunctions have been grown. In some cases, valence changes in the rare earth element cause doping of the alloy. Some initial investigations of the addition of europium to indium antimonide will also be reported, including the variation of lattice parameter and optical transmission with composition and a negative magnetoresistance effect.

Electronic and Optical Properties of Si/SiO2 Superlattices from First Principles: Role of Interfaces.

2001 ◽  
Vol 677 ◽  
Author(s):  
Pierre Carrier ◽  
Gilles Abramovici ◽  
Laurent J. Lewis ◽  
M. W. C. Dharma-wardana
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Energy Gap ◽  
Local Density ◽  
Interband Transition ◽  
Theoretical Research ◽  
Slab Thickness ◽  
Full Potential ◽  
Wave Method

ABSTRACTThe observation of intense luminescence in Si/SiO2 superlattices (SLs) has lead to new theoretical research on silicon-based materials. We have performed first-principles calculations using three Si/SiO2 SL models in order to examine the role of interfaces on the electronic structure and optical properties. The first two models are derived directly from crystalline structures and have simple interfaces. These models have been studied using the full-potential, linearized-augmented-plane-wave method, in the local-density-approximation (LDA). The optical absorption within the interband transition theory (excluding excitonic effects) have been deduced. The Si(001)-SiO2 interface structure is shown to affect the optical behaviour. Following these observations, we have considered a more realistic, fully-relaxed model. The projector-augmented-wave method under the LDA is used to perform the structural relaxation as well as band structure and optical calculations. The role of confinement on the energy gap is studied by inserting additional silicon slabs into the supercell. Direct energy gaps are observed and the energy gap is found to decrease with increasing silicon slab thickness, as observed experimentally. The role of the interface has been considered in more details by studying the contribution to the energy gap of Si atoms having different oxidation patterns; partially oxidized Si atoms at the interface, as well as Si atoms inside the Si layer, are shown to contribute to the transitions at the energy gap.

The Role of Hydrogen in Semi-Insulating Inp

1998 ◽  
Vol 513 ◽  
Author(s):  
Yujie Han ◽  
Xunlang Liu ◽  
Jinghua Jiao ◽  
Jiajun Qian ◽  
Yonghai Chen ◽  
...  
Keyword(s):  
Energy Level ◽  
Energy Gap ◽  
Electronic States ◽  
Extended Defects ◽  
Acceptor Level ◽  
Hydrogen Atoms ◽  
Deep Acceptor ◽  
Deep Acceptor Level ◽  
Deep Donor

ABSTRACTComplexes of vacancy at indium site with one to four hydrogen atoms and isolated hydrogen or hydrogen dimer and other infrared absorption lines, tentatively be assigned to hydrogen related defects were investigated by FTIR. Hydrogen can passivate imperfections, thereby eliminating detrimental electronic states from the energy bandgap.Incorporated hydrogen can introduce extended defects and generate electrically-active defects. Hydrogen also can acts as an actuator for creating of antistructure defects. Isolated hydrogen related defects(e.g. H12+) may play an important role in the conversion of the annealed wafers from semiconducting to the semi-insulating behavior. H2+ may be a deep donor, whose energy level is very near the iron deep acceptor level in the energy gap.

Dependence of energy gap onxandTinZn1−xMnxSe: The role of exchange interaction

1986 ◽  
Vol 33 (12) ◽  
pp. 8207-8215 ◽  
Author(s):  
R. B. Bylsma ◽  
W. M. Becker ◽  
J. Kossut ◽  
U. Debska ◽  
D. Yoder-Short
Keyword(s):  
Exchange Interaction ◽  
Energy Gap

scholarly journals Structural, Thermal and Optical Properties of Rare Earth Doped Lead-Tellurite Oxide Glasses

2021 ◽  
Vol 81 (2) ◽  
pp. 52-58
Author(s):  
Fong W. L. ◽  
Sharudin Omar Baki ◽  
N. M. Arifin ◽  
Yaakob Mansor ◽  
Ahmad Nazri ◽  
...  
Keyword(s):  
Optical Properties ◽  
Rare Earth ◽  
Energy Gap ◽  
Structural Deformation ◽  
Oxide Glasses ◽  
X Ray Diffraction ◽  
Optical Energy Gap ◽  
Erbium Ions ◽  
Glass Transformation

Structural, thermal and optical properties of lead-tellurite oxide glasses consisting TeO2 – PbO – Bi2O3 – Er2O3, synthesized by high temperature melt-quenching-thermal annealing method were investigated in this study. The role of rare-earth element, erbium ion as dopant into the host glass has affected physically, thermally and optically of the glasses. The amorphous nature of the glasses was confirmed by XRD (x-ray diffraction). Thermal exo-endothermic event profiles clarify its glass transformation temperature Tg, crystallization temperature Tx, and melting temperature Tm are exist. Both UV-Vis-NIR optical absorption and Raman spectroscopy have revealed optical energy gap changes due to the structural deformation by the erbium ions. Related obtained glass parameters such as polarizability, refractive indices and metallization criterion were also explained further in this study.

scholarly journals The Role of Iodine Catalyst in the Synthesis of 22-Carbon Tricarboxylic Acid and Its Ester: A Case Study

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 972
Author(s):  
Liu ◽  
Zhang ◽  
Wang ◽  
Zan ◽  
Zhang
Keyword(s):  
Energy Gap ◽  
Tricarboxylic Acid ◽  
Alder Reaction ◽  
Diels Alder ◽  
Proton Nuclear Magnetic Resonance ◽  
Ionization Mass ◽  
Double Bonds ◽  
Chemical Structures ◽  
Diels Alder Reaction

Here, 22-carbon tricarboxylic acid (C22TA) and its ester (C22TAE) were prepared via the Diels–Alder reaction of polyunsaturated fatty acids (PUFAs) and their esters (PUFAEs) as dienes with fumaric acid (FA) and dimethyl fumarate (DF) as dienophiles, respectively. The role of an iodine catalyst for the synthesis of C22TA and C22TAE in the Diels–Alder type reaction was investigated using a spectroscopic approach. The chemical structures of the products were characterized using proton nuclear magnetic resonance (1H-NMR) and electrospray ionization mass spectrometry (ESI-MS) analysis. Results showed that nonconjugated dienes can react with dienophiles through a Diels–Alder reaction with an iodine catalyst, and that iodine transformed the nonconjugated double bonds of dienes into conjugated double bonds via a radical process. DF was more favorable for the Diels–Alder reaction than FA. This was mainly because the dienophile DF contained an electron-withdrawing substituent, which reduced the highest and lowest occupied molecular orbital (HOMO–LUMO) energy gap and accelerated the Diels–Alder reaction. By transforming nonconjugated double bonds into conjugated double bonds, iodine as a Lewis acid increased the electron-withdrawing effect of the carbonyl group on the carbon–carbon double bond and reduced the energy difference between the HOMO of diene and the LUMO of dienophile, thus facilitating the Diels–Alder reaction.

The role of the Ca vacancy in the determination of the europium position in the energy gap, its valence state and spectroscopic properties in KCa(PO3)3

2014 ◽  
Vol 16 (12) ◽  
pp. 5581 ◽  
Author(s):  
A. Watras ◽  
A. Matraszek ◽  
P. Godlewska ◽  
I. Szczygieł ◽  
J. Wojtkiewicz ◽  
...  
Keyword(s):  
Valence State ◽  
Energy Gap ◽  
Spectroscopic Properties
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