Interstitial O isotope effects in silicon

Pajot, B.; Artacho, Emilio; Ammerlaan, C.A.J.; Spaeth, J.‐M.

doi:10.1088/0953-8984/7/35/015

Cited by 33 publications

(29 citation statements)

References 14 publications

(2 reference statements)

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“…The low-energy satellites are reminiscent of those due to Si isotope effects in vibrational spectra like those of interstitial oxygen. 17 The high-frequency satellite can be related to the 34 S isotope, whose natural relative abundance with respect to 32 S is 0.045. No contribution of 33 S, expected to lie midway between the 32 S and 34 S components, is detected in this sample.…”

Section: B the 1s"t 2 … Components Of S ¿mentioning

confidence: 99%

Isotope effects in the electronic spectrum ofS+andSe+in silicon

Pajot¹,

Clerjaud

McCluskey

2004

Phys. Rev. B

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Weak satellites of the strong and sharp parity-forbidden, but symmetry-allowed 1s(A 1 )→1s(T 2 ) doublet of the S ϩ donor spectrum in silicon are reported. The low-energy ones are ascribed to a Si isotope effect and the high-energy ones to an S isotope effect. We also show that the profile of the low-energy component of the same transition of Se ϩ in silicon can be reproduced from the computed combination of Si and Se isotope shifts with the same characteristics as those of S ϩ , but with a smaller Se isotope shift. The Si isotope shift is discussed in terms of the bond softening effect in the electronic ground state for a cluster involving the chalcogen atom and its first nearest neighbors. The positive chalcogen isotope shift is discussed by considering the effect of a vibronic coupling to the 2 mode of vibration in the excited state within the bond softening framework. It is also shown that this vibronic coupling can account for the noneffective mass behavior of the 1s(T 2 ) level.

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Section: B the 1s"t 2 … Components Of S ¿mentioning

confidence: 99%

Isotope effects in the electronic spectrum ofS+andSe+in silicon

Pajot¹,

Clerjaud

McCluskey

2004

Phys. Rev. B

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“…These are compared with values obtained previously 32,37,34 and the observed modes. 38,29,39 The frequencies for the combination bands were obtained by summing the fundamental modes.…”

Section: Simentioning

confidence: 99%

Oxygen and dioxygen centers in Si and Ge: Density-functional calculations

et al. 2000

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Ab initio density-functional calculations using Gaussian orbitals are carried out on large Si and Ge supercells containing oxygen defects. The formation energies, local vibrational modes, and diffusion or reorientation energies of O i , O 2i , VO, VOH, and VO 2 are investigated. The piezospectroscopic tensors for O i , VO, and VO 2 are also evaluated. The vibrational modes of O i in Si are consistent with the view that the defect has effective D 3d symmetry at low hydrostatic pressures but adopts a buckled structure for large pressures. The anomalous temperature dependence of the modes of O 2i is attributed to an increased buckling of Si-O-Si when the lattice contracts. The diffusion energy of the dimer is around 0.8 eV lower than that of O i in Si and 0.6 eV in Ge. The dimer is stable against VO or VO 2 formation and the latter defect has modes close to the reported 894-cm Ϫ1 band. The reorientation energies for O and H in VO and VOH defects are found to be a few tenths of an eV and are greater when the defect has trapped an electron.

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“…1. [11][12][13][14][15] Ab initio calculations have shown the bond lengths of Si-O to be 1.59 Å, with the most probable Si-O-Si bond angle 172°. 16 An interstitial oxygen atom has 2 equivalent nearest-neighbor Si atoms, 6 equivalent second-nearest-neighbor Si atoms, 18 equivalent thirdneighbor Si atoms, and so on.…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, the discovery that the LVM linewidth of 17 O is a factor of 1.5 larger than those of 16 O and 18 O in nat Si has suggested strongly that the interaction between Si phonons and oxygen LVM's determines the lifetime of the oxygen LVM's in silicon. 14 In order to understand the interaction between the bulk Si isotopes and vibrating oxygen atoms, two factors must be considered separately: ͑i͒ the energy dependence of the multiphonon emissivity, which is determined mainly by the average mass of the constituent Si isotopes, and ͑ii͒ disorder in Si masses ͑disorder in the Si isotope distribution͒, which arises from the copresence of 28 Si, 29 Si, and 30 Si isotopes. While the larger linewidth of 17 O is most likely due to the former effect, the effect of isotopic disorder is predicted to be negligibly small within the framework of the harmonic approximation, as we will show later.…”

Section: Introductionmentioning

confidence: 99%

Host isotope effect on the localized vibrational modes of oxygen in isotopically enriched28Si,29
Katō
¹
,
Itoh
²
,
Yamada-Kaneta
³

et al. 2003
Phys. Rev. B
25
2
10
0
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A high-resolution infrared absorption study of the localized vibrational modes ͑LVM's͒ of oxygen in isotopically enriched 28 Si, 29 Si, and 30 Si single crystals is reported. Isotope shifts of LVM frequencies from those in natural Si are clearly observed not only due to the change of the average mass in the nearest-neighbor silicon atoms, but also to the combined effect of the ͑i͒ change in Si masses of the second and beyond nearest neighbors and ͑ii͒ change in the lattice constants of the host Si crystals. These conclusions have been drawn based on a direct comparison between the experimental results and theoretical calculations assuming harmonic potentials for localized vibrations of oxygen. However, the LVM linewidths of the A 2u mode in the enriched samples are much narrower than those in natural Si, despite the fact that the harmonic approximation predicts very little dependence of the width on the host Si isotopic composition. This observation suggests that both anharmonicity and inhomogeneous broadening due to isotopic disorder are playing important roles in the determination of oxygen LVM linewidths. Moreover, a new series of oxygen LVM peaks is observed clearly in the isotopically enriched samples thanks to the small degree of mass disorder.

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Interstitial O isotope effects in silicon

Cited by 33 publications

References 14 publications

Isotope effects in the electronic spectrum ofS+andSe+in silicon

Isotope effects in the electronic spectrum ofS+andSe+in silicon

Oxygen and dioxygen centers in Si and Ge: Density-functional calculations

Host isotope effect on the localized vibrational modes of oxygen in isotopically enriched28Si,29
Katō
¹
,
Itoh
²
,
Yamada-Kaneta
³

et al. 2003
Phys. Rev. B
25
2
10
0
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Interstitial O isotope effects in silicon

Cited by 33 publications

References 14 publications

Isotope effects in the electronic spectrum ofS+andSe+in silicon

Isotope effects in the electronic spectrum ofS+andSe+in silicon

Oxygen and dioxygen centers in Si and Ge: Density-functional calculations

Host isotope effect on the localized vibrational modes of oxygen in isotopically enriched28Si,29Katō1, Itoh2, Yamada-Kaneta3 et al. 2003Phys. Rev. B252100View full textAdd to dashboardCite

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Host isotope effect on the localized vibrational modes of oxygen in isotopically enriched28Si,29
Katō
¹
,
Itoh
²
,
Yamada-Kaneta
³

et al. 2003
Phys. Rev. B
25
2
10
0
View full text Add to dashboard Cite