Direct Measurement of Electron Emission from Defect States at Silicon Grain Boundaries

1980 ◽  
Vol 44 (20) ◽  
pp. 1365-1365
Author(s):  
C. H. Seager ◽  
G. E. Pike ◽  
D. S. Ginley
Keyword(s):  
Grain Boundaries ◽  
Direct Measurement ◽  
Electron Emission ◽  
Defect States

Charged defect states at silicon grain boundaries

1986 ◽  
Vol 60 (11) ◽  
pp. 3910-3915 ◽  
Author(s):  
F. J. Stützler ◽  
H. J. Queisser
Keyword(s):  
Grain Boundaries ◽  
Charged Defect ◽  
Defect States

Direct measurement of non-equilibrium solute segregation to grain boundaries

1969 ◽  
Vol 3 (9) ◽  
pp. 663-665 ◽  
Author(s):  
S.J. Bercovici ◽  
P. Niessen ◽  
J.J. Byerley
Keyword(s):  
Grain Boundaries ◽  
Direct Measurement ◽  
Solute Segregation ◽  
Non Equilibrium

Mesoscopic Model for The Laser-Target Interaction

1998 ◽  
Vol 526 ◽  
Author(s):  
R. Mendes Ribeiro ◽  
Marta M.D. Ramos ◽  
A.M. Stoneham
Keyword(s):  
Grain Boundaries ◽  
Electric Fields ◽  
Electron Emission ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Defect Concentration ◽  
Laser Target ◽  
Target Interaction ◽  
Mesoscopic Model ◽  
Species Removal

AbstractWe have developed a mesoscopic model for the study of pulsed laser ablation of transparent granular ceramics. The model enables the understanding of several features that happen at the surface of a transparent target and which play an important role in the evolution of the evaporation process.The results show that electron emission happens early, much before atom evaporation. High defect concentration regions (including grain boundaries, surface) are crucial for energy absorption. The model also predicts the generation of high intensity electric fields in places with high defect concentration, such as grain boundaries. Low fluences should have selective species removal, but higher fluences should give congruent removal.The dependence of the density of generated electrons, the evaporated species and energy on the material properties is included.

scholarly journals Morphology and Electron Emission Properties of Nanocrystalline CVD Diamond Thin Films

1997 ◽  
Vol 495 ◽  
Author(s):  
Alan R. Krauss ◽  
Dieter M. Gruen ◽  
Daniel Zhou ◽  
Thomas G. Mccauley ◽  
Lu Chang Qin ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Hydrogen Concentration ◽  
Electron Emission ◽  
Microwave Plasma ◽  
Initial Growth ◽  
Average Grain Size ◽  
Diamond Thin Films

ABSTRACTNanocrystalline diamond thin films have been produced by microwave plasma-enhanced chemical vapor deposition (MPECVD) using C60/Ar/H2 or CH4/Ar/H2 plasmas. Films grown with H2 concentration ≤ 20% are nanocrystalline, with atomically abrupt grain boundaries and without observable graphitic or amorphous carbon phases. The growth and morphology of these films are controlled via a high nucleation rate resulting from low hydrogen concentration in the plasma. Initial growth is in the form of diamond, which is the thermodynamic equilibrium phase for grains < 5 nm in diameter. Once formed, the diamond phase persists for grains up to at least 15–20 nm in diameter. The renucleation rate in the near-absence of atomic hydrogen is very high (∼1010 cm2sec−1), limiting the average grain size to a nearly constant value as the film thickness increases, although the average grain size increases as hydrogen is added to the plasma. For hydrogen concentrations less than ∼20%, the growth species is believed to be the carbon dimer, C2, rather than the CH3* growth species associated with diamond film growth at higher hydrogen concentrations. For very thin films grown from the C60 precursor, the threshold field (2 to ∼60 volts/micron) for cold cathode electron emission depends on the electrical conductivity and on the surface topography, which in turn depends on the hydrogen concentration in the plasma. A model of electron emission, based on quantum well effects at the grain boundaries is presented. This model predicts promotion of the electrons at the grain boundary to the conduction band of diamond for a grain boundary width ∼3–4 Å, a value within the range observed by TEM.

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