Solid atomic hydrogen: Point defect formation and elastic stability

Formation entropy of point defects is one of the last crucial elements required to fully describe the temperature dependence of point defect formation. However, while many attempts have been made to compute them for very complicated systems, very few works have been carried out such as to assess the different effects of finite size effects and precision on such quantity. Large discrepancies can be found in the literature for a system as primitive as the silicon vacancy. In this work, we have proposed a systematic study of formation entropy for silicon vacancy in its 3 stable charge states: neutral, +2 and –2 for supercells with size not below 432 atoms. Rationalization of the formation entropy is presented, highlighting importance of finite size error and the difficulty to compute such quantities due to high numerical requirement. It is proposed that the direct calculation of formation entropy of VSi using first principles methods will be plagued by very high computational workload (or large numerical errors) and finite size dependent results.

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Point Defect Kinetics and Extended-Defect Formation during Millisecond Processing of Ion-Implanted Silicon

Topics in Applied Physics - Materials Science with Ion Beams ◽

10.1007/978-3-540-88789-8_7 ◽

2009 ◽

pp. 213-226

Author(s):

K. Gable ◽

K. S. Jones

Keyword(s):

Point Defect ◽

Defect Formation ◽

Extended Defect ◽

Ion Implanted

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Native Point Defect Densities and Dark Line Defects in ZnSe

MRS Proceedings ◽

10.1557/proc-408-503 ◽

1995 ◽

Vol 408 ◽

Author(s):

M. A. Berding ◽

A. Sher ◽

M. Van Schilfgaarde

Keyword(s):

Free Energy ◽

Point Defect ◽

Defect Formation ◽

Local Density ◽

Full Potential ◽

Nonradiative Recombination ◽

Dark Line ◽

Frenkel Defect ◽

Native Point Defect ◽

Defect Densities

AbstractNative point defect densities (including vacancies, antisites and interstitials) in ZnSe are calculated using a quasichemical formalism, including both vibrational and electronic contributions to the defect free energy. The electronic contribution to the defect formation free energy is calculated using the self-consistent first-principles full-potential linearized muffin-tin orbital (FP-LMTO) method and the local-density approximation (LDA). Gradient corrections are included so that absolute reference to zinc atoms in the vapor phase can be made. We find that the Frenkel defect formation energy is ∼0.3 eV lower at a stacking fault than in the bulk lattice. Nonradiative-recombination-induced Frenkel defect generation at stacking faults is proposed as a mechanism responsible for the limited device lifetimes.

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