forbidden band


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forbidden band

n
(General Physics) See energy band
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
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This is related to the fact that the conduction band of the adsorbed Ag metal particles on alumina structure can coat the valence band and the part of forbidden band under the Fermi energy level.
There is no impurity energy level in the forbidden band because the Si and Ti atoms showed equal valencies.
The distance between the highest point of the Fermi energy level valence band (EV) and the lowest point of the conduction band (Ec) can be used to determine the energy required for valence electrons to move to the conduction band, which is also known as the forbidden band or the band gap.
This Bloch-Floquet analysis has been carried out, for instance, in [14, 28] to explain the stopband common-mode operation of the proposed structures in terms of the forbidden band of the periodic structures.
The range of the obtained omnidirectional forbidden band is from 0.825 [micro]m to 1.563 [micro]m.
When a practical three-dimensional (3D) PhC is considered, the dispersion relation near the forbidden band edge exhibits a directional-dependent property and thus has been expressed as a vector form by the effective-mass approximation [33].
The defects of [S.sub.1] and [V.sub.Cu] play a dominant role in the [Cu.sub.2]Sn[S.sub.3] thin films and may form impurity band in the forbidden band. When the acceptor impurity band exists in the films, the mobility [[mu].sub.p] is related to the hole mobility in the valence band [[mu].sub.v] and the mobility in the impurity band [[mu].sub.i] which was reported by Emelyanenko et al.
Lin proposes a new phenomenon in which photons having wavelengths just outside a crystal's forbidden band cling to the metal lattice.
The absorption mechanism for the photons is mainly decided by the width of the forbidden band of the material itself; as long as the photon energy is larger than the width of the forbidden band of the material, then the material can undergo the transition between the top of the valence band and the bottom of the conduction band [23-25].
Now, a member of that research group, Francisco Meseguer of the Polytechnic University of Valencia in Spain, reports that the scientists have created a structure of rods in air that stops sound in the forbidden band from every angle.
From Figure 2(a), we can see that only one forbidden band has been formed in range from 428 nm to 577 nm, and it shows that the resonant peaks on the left side are dense and irregular, while the resonant peaks on the right side are regular.