Vacancies and E-centers in silicon as multi-symmetry defects

Ganchenkova, Maria; Oikkonen, L. E.; Бородин, В. А.; Nicolaysen, S.; Nieminen, Risto M.

doi:10.1016/j.mseb.2008.10.040

Cited by 15 publications

(16 citation statements)

References 34 publications

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“…Our results agree with these facts. We also confirm the existence of several metastable structures with the charge other than +2 that have nearly the same energy [24,25,28,29]. The length of the dimer in V 0 1 decreases with the cell size and saturates at about 0.31 nm.…”

Section: Results For Finite Supercellssupporting

confidence: 74%

“…And it makes an illustrative case of Jahn-Teller distortions [4,15,20,36], being the first proven example of negative Hubbard U [4,15,18,30,37]. It combines with impurities [29], forming complexes like the A center [38] (with O) or the E center [39] (with P), and also with other defects, including other vacancies. Si vacancies and their agglomerates must thus be dealt with in the simulation of various defect-related processes, such as dopant implantation, rapid thermal annealing (RTA), and SiO 2 precipitation.…”

Section: Introductionmentioning

confidence: 99%

“…This is easy to implement and employs mature numerical procedures, and its accuracy due to the finite basis set can be tested systematically. This method has been widely used also for V 1 and its clusters V n [20][21][22][23][24][25][26][27][28][29][30][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67]. Yet it suffers from spurious effects caused by interaction between defects in the superlattice produced by the PBC [69].…”

Section: Introductionmentioning

confidence: 99%

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Supercell-size convergence of formation energies and gap levels of vacancy complexes in crystalline silicon in density functional theory calculations

Dąbrowski

Kissinger

2015

Phys. Rev. B

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Results for supercell-size convergence of formation energies and charge transition levels of vacancy complexes V n (1 n 11) in crystalline Si are reported for the ab initio density functional theory (DFT) with generalized gradient approximation (GGA) pseudopotentials. When extrapolated to the dilute limit, the formation energy of an uncharged vacancy becomes 3.74 ± 0.1 eV, and the binding energy of an uncharged divacancy becomes 1.9 ± 0.2 eV. Stable V n clusters are built on the basis of sixfold rings (n 6) and of octahedral voids (n 7). If the well-known underestimate of the band gap by the DFT and the accuracy of extrapolations are taken into account, the extrapolated levels are in good agreement with experiment. We discuss the implications for simulation of vacancy clustering during thermal quenching, for interpretation of deep-level spectroscopy and electron paramagnetic resonance in irradiated Si, and for cell and Brillouin-zone sampling choice when DFT-related methods beyond local-density approximation or GGA are used.

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Section: Results For Finite Supercellssupporting

confidence: 74%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Supercell-size convergence of formation energies and gap levels of vacancy complexes in crystalline silicon in density functional theory calculations

Dąbrowski

Kissinger

2015

Phys. Rev. B

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“…For charge state +2, the energy of the T d structure is 0.15 eV lower than the one of D 2d while for the −2 charge state, a split vacancy with D 3d symmetry is 0.2 eV more stable compared to the second lowest energy structure, C 2v . All the ground state structures found for charge states 0, +2 and -2 are in agreement with previous theoretical studies [35][36][37][38]49] and with DLTS and EPR studies of Watkins [40,50]. As Table 1 shows, the main discrepancies between previously published results occur for the defect charge states +1 and -1.…”

Section: Technical Detailssupporting

confidence: 89%

On the ab initio calculation of vibrational formation entropy of point defect: the case of the silicon vacancy

Seeberger

Vidal

2017

EPJ Photovolt.

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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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“…Moreover, defects of the same rank can exist in clusters of different shape, which is the manifestation of the multiconfigurational nature of basic point defects in silicon. 46 144118-11 FIG. 14.…”

Section: Methodological Aspectsmentioning

confidence: 99%

Synergetic effects of dual-beam implantation on the microstructural development in silicon

et al. 2011

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We report a synergy effect on the microstructural development of silicon specimens as a result of dual-beam high temperature irradiation/implantation. In situ transmission electron microscopy experiments using two different experimental setups have been used, where the primary 50 keV Co+ ion implantation beam was supplemented with either a 300 keV electron beam or a 500 keV Si+ ion beam. In both cases, the secondary beam intensity was such that both beams created comparable overall primary damage. Completely different microstructural response has been found in these two cases. An intensive electron irradiation was found to sharply accelerate the evolution of dislocation structure, only weakly affecting the disilicide kinetics. On the contrary, the Si ion beam weakly affected the kinetics of either dislocation loops or coherent CoSi2 precipitates, but drastically increased the number density of thermodynamically unstable semicoherent precipitates. Possible microstructural reasons for the observed effects and the implications for both dislocation loop and cobalt disilicide nucleation mechanisms in high-temperature implanted TEM samples are discussed and supported by detailed molecular dynamics calculations of annealing of cascade remnants produced by the energetic silicon recoils

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Vacancies and E-centers in silicon as multi-symmetry defects

Cited by 15 publications

References 34 publications

Supercell-size convergence of formation energies and gap levels of vacancy complexes in crystalline silicon in density functional theory calculations

Supercell-size convergence of formation energies and gap levels of vacancy complexes in crystalline silicon in density functional theory calculations

On the ab initio calculation of vibrational formation entropy of point defect: the case of the silicon vacancy

Synergetic effects of dual-beam implantation on the microstructural development in silicon

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