First Principles Analysis of Ultra-Thin Silicon Films with Dimer Structures

2011 ◽  
Vol 1370 ◽  
Author(s):  
Eiji Kamiyama ◽  
Koji Sueoka
Keyword(s):  
Thin Film ◽  
First Principles ◽  
Silicon On Insulator ◽  
First Principles Calculation ◽  
Self Energy ◽  
Plate Models ◽  
Bulk Model ◽  
Si Films ◽  
The Impact ◽  
Si Thin Film

ABSTRACTThe impact of dimer formations at the surfaces of the internal atoms of silicon (Si) thin film was evaluated by examining silicon-on-insulator (SOI) and plate models. In the SOI models, a dimer formation was modeled at one side of the Si thin film. The plate models had two dimers at each surface, which had been considered as a Si bulk model in previous studies. First principles calculation showed that the deviations of Si atoms from the first to fourth layers of the SOI models did not differ remarkably from those of the plate models. The internal atoms deeper than the fifth layer showed near-zero deviation in some of the SOI models and had evident non-zero deviation in the other SOI models. All the SOI and plate models showed lower Si atom self-energy than in the Si bulk. The layer-to-layer distance of internal atoms in the films became longer than that of atoms in Si bulk. These results indicated that (i) Si films with dimer surfaces are relaxed by deviations in the whole film, and (ii) even the thick plate model with 32 layers dose not reveal the nature of Si bulk.

First-Principles Calculation for Improving Room Temperature Ductility of B2-NiAl by Fe

2011 ◽  
Vol 327 ◽  
pp. 94-99
Author(s):  
Yu Xiang Lu ◽  
Guo Liang Qi ◽  
Liang Cheng
Keyword(s):  
First Principles ◽  
Room Temperature ◽  
Nearest Neighbor ◽  
Function Theory ◽  
Population Analysis ◽  
First Principles Calculation ◽  
Generalized Gradient ◽  
Generalized Gradient Approximation ◽  
Room Temperature Ductility ◽  
The Impact

Generalized gradient approximation (GGA) of the density function theory (DFT) was applied to calculate many properties including density of states, population analysis and electron density in NiAl and NiAl(Fe) to investigate the mechanism of improving room temperature ductility of B2-NiAl by Fe. It was shown that the strong bond to Al p and Ni d hybridization, which leads to the embrittlement of B2-NiAl at room temperature. Addition of Fe, which is beneficial to improve ambient ductility of B2-NiAl, weakens the impact of the bond to Al p and Ni d hybridization and enhances the interaction among next-nearest-neighbor Ni atoms to make the charge distribution uniform along <100>.

Monocrystalline Si Films from Transfer Processes for Thin Film Devices

2001 ◽  
Vol 685 ◽  
Author(s):  
Ralf B. Bergmann ◽  
Christopher Berge ◽  
Titus J. Rinke ◽  
Jürgen H. Werner
Keyword(s):  
Thin Film ◽  
Epitaxial Growth ◽  
Defect Density ◽  
Silicon On Insulator ◽  
Active Matrix ◽  
Plastic Substrates ◽  
Light Point ◽  
Single Host ◽  
Active Matrix Displays ◽  
Si Films

AbstractThe transfer of thin monocrystalline silicon films to foreign substrates is of great interest for a number of applications such as silicon on insulator devices, active matrix displays and thin film solar cells. We present a transfer approach for the fabrication of monocrystalline Si films on foreign substrates based on the formation ofquasi-monocrystallineSi-films. Our transfer approach is compatible with high temperature processing such as epitaxial growth at 1100°C, thermal oxidation and phosphorous diffusion. Reuse of Si host wafers is demonstrated by the subsequent epitaxial growth of three monocrystalline Si films on a single host wafer. Monocrystalline Si films with a thickness of 15 µm and a diameter of 3” are transferred to glass and flexible plastic substrates. The typical light point defect density in films transferred from virgin wafers ranges between 10 to 100 cm−2, while stacking fault and dislocation densities are ≤ 100 cm−2. The minority carrier diffusion length in the epitaxial Si films is around 50 µm.

Fast deposition of microcrystalline Si films from SiH2Cl2 using a high-density microwave plasma source for Si thin-film solar cells

2010 ◽  
Vol 94 (3) ◽  
pp. 524-530 ◽  
Author(s):  
Jhantu Kumar Saha ◽  
Naoyuki Ohse ◽  
Kazu Hamada ◽  
Hiroyuki Matsui ◽  
Tomohiro Kobayashi ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Microwave Plasma ◽  
Plasma Source ◽  
High Density ◽  
Thin Film Solar Cells ◽  
Si Films ◽  
Si Thin Film
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