Atomic relaxation and electronic structure of dilute alloys in the tight-binding approximation

1985 ◽  
Vol 52 (5) ◽  
pp. 971-985 ◽  
Author(s):  
G. Moraitis ◽  
B. Stupfel ◽  
F. Gautier
Keyword(s):  
Electronic Structure ◽  
Tight Binding ◽  
Tight Binding Approximation ◽  
Dilute Alloys ◽  
Atomic Relaxation

Luminescent Amorphous Silicon Layers

1997 ◽  
Vol 486 ◽  
Author(s):  
G. Allan ◽  
C. Delerue ◽  
M. Lannoo
Keyword(s):  
Electronic Structure ◽  
Amorphous Silicon ◽  
Radiative Recombination ◽  
Crystalline Silicon ◽  
Tight Binding ◽  
Blue Shift ◽  
Localized States ◽  
Structure Model ◽  
Radiative Recombination Rate ◽  
Tight Binding Approximation

AbstractThe electronic structure of amorphous silicon layers has been calculated within the empirical tight binding approximation using the Wooten-Winer-Weaire atomic structure model. We predict an important blue shift due to the confinement for layer thickness below 3 nm and we compare with crystalline silicon layers. The radiative recombination rate is enhanced by the disorder and the confinement but remains quite small. The comparison of our results with experimental results shows that the density of defects and localized states in the studied samples must be quite small.

Local Electronic Structure and Short-Range Order in a Computer Simulated Amorphous Metal

1991 ◽  
Vol 02 (01) ◽  
pp. 232-237 ◽  
Author(s):  
A.Ya. BELENKII ◽  
M.A. FRADKIN
Keyword(s):  
Electronic Structure ◽  
Short Range ◽  
Short Range Order ◽  
Local Density ◽  
Tight Binding ◽  
Amorphous Metal ◽  
Range Order ◽  
Tight Binding Approximation ◽  
Electronic Parameters ◽  
Local Electronic Structure

The relationship between topological short-range order and a local electronic structure was analyzed in the computer model of an amorphous metal. The model, obtained by means of the original self-consistent cluster simulation procedure was studied with the use of Voronoi tesselation, the distribution of the atomic level stresses and the icosahedral order parameters. It was found that a marked correlation exists within 2 atomic parameter groups, one of which corresponds to the local dilatation and the other to the spherical symmetry distortion. The local density of electronic d-states (DOS) and the distribution of the electronic parameters was analyzed. The local electronic structure, calculated within the tight-binding approximation, appears to depend on the local atomic order by two-fold means: the interatomic distances decrease leads to the increase of the local bandwidth, and the icosahedral configuration distortion reduces the DOS at the Fermi level. The study of the local configurations stability shows, that the most stable configurations are the slightly distorted icosahedra.

Electronic Structure of Amorphous Silicon

1997 ◽  
Vol 491 ◽  
Author(s):  
G. Allan ◽  
C. Delerue ◽  
M. Lannoo
Keyword(s):  
Electronic Structure ◽  
Amorphous Silicon ◽  
Tight Binding ◽  
Localized States ◽  
Band Offset ◽  
Valence Band Offset ◽  
Tight Binding Approximation ◽  
Exponential Tails ◽  
Si Model ◽  
Hydrogenated Amorphous

ABSTRACTThe electronic structure of a continuous network model of tetrahedrally bonded amorphous silicon (a-Si) and of a model hydrogenated amorphous silicon (a-Si:H) that we have built from the a-Si model are calculated in the tight binding approximation. The band edges near the gap are characterized by exponential tails of localized states induced mainly by the variations in bond angles. The spatial localization of the states is compared between a-Si and a-Si:H. Valence band offset between the amorphous and the crystalline phases is calculated.

Electronic Structure of CBN Ball Within Tight-Binding Approximation

1992 ◽  
Vol 9 (11) ◽  
pp. 581-584 ◽  
Author(s):  
Liu Jingnan ◽  
Huang Mingwei ◽  
Gu Binglin
Keyword(s):  
Electronic Structure ◽  
Tight Binding ◽  
Tight Binding Approximation

Orbitals and bands at metal surfaces: photoemission from the {110} surface of tungsten

1981 ◽  
Vol 376 (1767) ◽  
pp. 565-583 ◽  
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Surface State ◽  
Photon Emission ◽  
Tight Binding ◽  
Tight Binding Approximation ◽  
The Third ◽  
Surface Brillouin Zone ◽  
Orbital Character ◽  
Bulk Band

The electronic structure of the {110} surface of tungsten has been investigated by using angle-resolved photoemission. A surface state has been identified and characterized throughout the surface Brillouin zone (s. B. z.). Its dispersion is found to correlate with the projected band gap between the third and fourth bands of the tungsten bulk band structure. It is identified by comparison with Inglesfield’s calculation as having predominantly m = 1 d-orbital character. With photon energies of 21.2 and 40.8 eV, intense photoemission from the surface state is only observed after surface Umklapp, whereas, with 16.8 eV, photon emission is observed in both the first and second s. B. zs. The applicability of the tight-binding approximation to the elucidation of the electronic structure of a metal surface is examined with particular reference to this surface state. A qualitative analysis of the observed photoemission intensities is consistent with emission from a tungsten e g orbital that is hybridized with e g orbitals on neighbouring atoms.

LOCAL ELECTRONIC STRUCTURE OF Tl2Ca2Ba2Cu3O10 AND COMPARISON WITH LA-OXIDES AND Y-OXIDES

1990 ◽  
Vol 04 (09) ◽  
pp. 1537-1549 ◽  
Author(s):  
HUAI-YU WANG ◽  
FU-SUI LIU ◽  
EN-GE WANG ◽  
CHONG-YU WANG
Keyword(s):  
Electronic Structure ◽  
Nearest Neighbor ◽  
Tight Binding ◽  
The Other ◽  
Tight Binding Approximation ◽  
Densities Of States ◽  
Local Electronic Structure ◽  
Electronic Densities

Local electronic densities of states of Tl 2 Ca 2 Ba 2 Cu 3 O 10 (2223) are calculated by tight-binding approximation. The nearest and the next-nearest neighbor transitions are considered, and the results are compared with each other. After the latter is considered, the densities of states are smoothened and the semiconductor-like characteristic of the Tl-O layers disappears. Through comparison of 2223 with the other two high Tc ceramics La 2−x Sr x CuO 4 and YBa 2 Cu 3 O 7−x, it is believed that they have the same leading superconductive mechanism besides inter-plane interactions.

Electronic Structure of C 70 Within the Tight-Binding Approximation

1993 ◽  
Vol 10 (5) ◽  
pp. 290-293
Author(s):  
Binglin Gu ◽  
Jingnan Liu ◽  
Mingwei Huang ◽  
Jialin Zhu
Keyword(s):  
Electronic Structure ◽  
Tight Binding ◽  
Tight Binding Approximation
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