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Mobility Gaps: A Mechanism for Band Gaps in Melanins
Science, 1972The semiconductor behavior of melanins is reviewed and compared with quantum mechanical models of conduction in amorphous solids. The available data are consistent with extensions of Mott's basic model for amorphous semiconductors, whereas they are inconsistent with crystalline semiconductor models.
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Band gap in NiO: A cluster study
Physical Review B, 1988The Mott-Hubbard gap U and the charge-transfer gap \ensuremath{\Delta} of solid NiO are estimated from ab initio calculations on the ${\mathrm{NiO}}_{6}^{10\mathrm{\ensuremath{-}}}$ cluster. Covalency in the essentially localized ${d}^{n}$ states and localization for the spatially extended O(2p) hole states are introduced by means of a limited ...
JANSSEN, GJM, NIEUWPOORT, WC
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Electromagnetic Band gap Structures
2007 IEEE Antennas and Propagation Society International Symposium, 2007Various features about the application of EBG materials in printed antenna design and electromagnetic scattering are presented and methods of analysis are introduced. It is shown that a microstrip antenna with EBG or PMC surface has a larger directivity and lower side and back lobe levels. Numerical results are presented.
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Study of Band-Gap Characteristics for Curved Electromagnetic Band-Gap Structures
TENCON 2006 - 2006 IEEE Region 10 Conference, 2006According to the reflection condition of optics Bragg, a curved electromagnetic band-gap structures is designed, and the band-gap characteristics of it is studied deeply. The effect of electromagnetic band-gap structure parameters and cylindrical structure parameters on band-gap characteristics are analyzed for the filrst time, and some useful ...
Tao Liu +3 more
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1990
The distinction between valence and conduction bands is discussed. Insulators, semiconductors, metals. Electrons and holes definition. Effective mass; sign convention of charge, mass and mobility. Semi-metals and narrow gap semiconductors. Band parameters for typical semiconductors, table. Constant energy surfaces in Brillouin zones.
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The distinction between valence and conduction bands is discussed. Insulators, semiconductors, metals. Electrons and holes definition. Effective mass; sign convention of charge, mass and mobility. Semi-metals and narrow gap semiconductors. Band parameters for typical semiconductors, table. Constant energy surfaces in Brillouin zones.
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Plasma expansion and band-gap renormalization in CdTe and GaP
Journal of Luminescence, 1985Abstract Detailed experimental and theoretical investigations, based on direct excite and probe experiments and on line-shape analysis, on the influence of many-body interaction, polar interaction, and transport effects on the energetic position and shape of the electron-hole plasma (EHP) emmission are reported.
H. SCHWEIZER, E. ZIELINSKI
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CLEO/Europe Conference on Lasers and Electro-Optics, 1998
Photonic band gaps are ranges of frequency within which electromagnetic propagation is completely forbidden. They are present in certain materials which possess a periodicity of permittivity at the wavelength scale. Materials with these extreme properties are not known to occur naturally, and.
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Photonic band gaps are ranges of frequency within which electromagnetic propagation is completely forbidden. They are present in certain materials which possess a periodicity of permittivity at the wavelength scale. Materials with these extreme properties are not known to occur naturally, and.
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Band-to-Band Auger Recombination in Indirect Gap Semiconductors
Physica Status Solidi (a), 1971Electron–hole pairs in semiconductors may recombine through an Auger process. The theory for this process was worked out by Beattie and Landsberg, for a semiconductor with a simple and direct band structure. They found that the conservation laws for energy and crystal momentum lead to a threshold energy for this type of recombination.
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