Role of Dangling Bond State Occupancy in Adsorption of Copper Phthalocyanine on Si(111)-Sn-√3 × √3

2019 ◽  
Vol 123 (26) ◽  
pp. 16232-16238
Author(s):  
Petr Zimmermann ◽  
Karel Majer ◽  
Pavel Kocán ◽  
Ivan Ošt’ádal ◽  
Pavel Sobotík
Keyword(s):  
Copper Phthalocyanine ◽  
Dangling Bond ◽  
Bond State

The Role of Charged Defects In Current Transport Through Hydrogenated Amorphous Silicon Alloys

1998 ◽  
Vol 507 ◽  
Author(s):  
S.P. Lau ◽  
J.M. Shannon ◽  
B.J. Sealy ◽  
J.M. Marshall
Keyword(s):  
Silicon Nitride ◽  
Amorphous Silicon ◽  
Defect Density ◽  
Current Transport ◽  
Dangling Bond ◽  
Silicon Alloys ◽  
Metal Structures ◽  
Bond State ◽  
Donor States ◽  
Charged Defects

ABSTRACTCurrent transport in metal-semiconductor-metal structures based on amorphous silicon alloys has been studied in relation to the density of dangling bond state defects. The density of defects was changed by varying alloy composition or by current stressing. We show that the change of current-voltage characteristics and activation energy with defect density and the onset of Poole-Frenkel conduction with composition require charged defects. It is found that there are more charged defects in amorphous silicon nitride (a-Si1−xNx:H) than in amorphous silicon carbide (a-Si1−xCx:H). In addition, an excess of negatively charged dangling bond defects compared to positively charged dangling bond defects is observed in a-Si1−xNx:H films. This is attributed to the presence of N4+ act as the donor states in silicon nitride. We find that the density of charged dangling bond defects can be higher than 1019cm−3.

The Influence of the Magnetic Field on the Current-Voltage Characteristics of CuPc Nanowires

2019 ◽  
Vol 970 ◽  
pp. 75-81
Author(s):  
Alexey Zavgorodniy ◽  
Aitbek Aimukhanov ◽  
Assylbek Zeinidenov ◽  
Galina Vavilova
Keyword(s):  
Magnetic Field ◽  
Carrier Transport ◽  
Copper Phthalocyanine ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Photosensitive Cell ◽  
Positively Charged

The role of spin states in the process of charge carrier transport in copper phthalocyanine (CuPc) nanowires has been established. According to the data obtained, CuPc nanowires are in the η-phase. The current-voltage characteristics (IVC) of a photosensitive cell based on CuPc nanowires in a magnetic field are investigated. As a result of experiments, it was found that applying an external magnetic field, the spins of two positively charged polarons are oriented in one direction. The channel of formation of the bipolaron is blocked. As a result, a decrease in the short-circuit current of the photosensitive cell is observed by more than 61%.

On the role of the dangling bond as a radiative centre in a-Si:H

1982 ◽  
Vol 41 (3) ◽  
pp. 263-267 ◽  
Author(s):  
S.P. Depinna ◽  
B.C. Cavenett ◽  
I.G. Austin ◽  
T.M. Searle
Keyword(s):  
Dangling Bond

Photoluminescence in Hydrogenated Silicon-Germanium Alloys

1987 ◽  
Vol 95 ◽  
Author(s):  
R. Ranganathan ◽  
M. Gal ◽  
J. M. Viner ◽  
P. C. Taylor
Keyword(s):  
Valence Band ◽  
Conduction Band ◽  
Silicon Germanium ◽  
Low Energy ◽  
Dangling Bond ◽  
Band Tail ◽  
Hydrogenated Silicon ◽  
Bond State ◽  
Constant Magnitude ◽  
Low Energy Tail

AbstractResults of a detailed study of photoluminescence (PL) in the a-Si1−xGex:H system are presented. Many samples exhibit a low energy “tail” to the PL efficiency which is of constant magnitude independent of x. There is a departure from this behavior when a low energy PL peak near 0.8–0.9 eV is present. The position of the low energy PL peak is independent of Ge concentration. It has been suggested that this PL transition is from an electron in the conduction band tail into a silicon dangling bond state. As Ge is added to a-Si:H it is the edge of the conduction band which decreases in energy while the valence band remains relatively constant in energy. It is therefore unlikely that the low energy PL is due to a transition from the conduction band into a silicon dangling bond state because the energy of the silicon dangling bond with respect to the valence band is probably essentially independent of Ge content. If the PL which peaks near 0.8 eV results from a transition which involves a silicon dangling bond, then the transition may be from the dangling bond to the valence band.

ANGLE-RESOLVED PHOTOEMISSION STUDIES OF THE 3C–SiC(001)(2×1) SURFACE

1999 ◽  
Vol 06 (06) ◽  
pp. 1151-1157 ◽  
Author(s):  
L. DUDA ◽  
L. S. O. JOHANSSON ◽  
B. REIHL ◽  
H. W. YEOM ◽  
S. HARA ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Synchrotron Radiation ◽  
Binding Energy ◽  
Brillouin Zone ◽  
Surface State ◽  
Electronic States ◽  
Dangling Bond ◽  
Poor Agreement ◽  
Bond State ◽  
Surface Brillouin Zone

We have investigated the electronic structure of the single-domain 3C–SiC(001)(2×1) using angle-resolved photoemission and synchrotron radiation. Two different surface-state bands are clearly identified within the bulk bandgap. The upper band has a binding energy of 1.4 eV at the center of the surface Brillouin zone (SBZ) and shows a weak dispersion of 0.3 eV in the [Formula: see text] direction, but is nondispersive in the perpendicular direction. It has a polarization dependence suggesting a pz character, as expected for a Si dangling-bond state. The second band is located at 2.4 eV binding energy and is nondispersive. The weak or nonexistent dispersions suggest very localized electronic states at the surface and show poor agreement with calculated dispersions for the proposed models for the 2×1 and c(4×2) reconstructions.

Electronic Structure and Dynamics of Defect in a-Si:H by Ab-Initio Molecular Dynamics

1993 ◽  
Vol 297 ◽  
Author(s):  
N. Orita ◽  
T. Sasaki ◽  
H. Katayama–Yoshida
Keyword(s):  
Molecular Dynamics ◽  
Electronic Structure ◽  
Ab Initio ◽  
Hydrogenated Amorphous Silicon ◽  
Ab Initio Molecular Dynamics ◽  
Dangling Bond ◽  
Structure And Dynamics ◽  
Dynamics Simulations ◽  
Hydrogenated Amorphous

Electronic structure and dynamics of defects in hydrogenated amorphous silicon (a-Si:H) are investigated based upon ab–initio molecular–dynamics simulations. It is shown that (i) the hydrogen–passivated dangling bond (Si-H), (ii) the positively-ionized three–centered bond (Si– H+–Si), (iii) the negatively–ionized three–coordinated dangling bond (D−) and (iv) the five- coordinated floating bond (F5) are the intrinsic defects in a–Si:H. Based upon the calculated result, we discuss the role of hydrogen and the origin of the photo–induced defect in a-Si:H.

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