Microscopic identification of native donor Ga-vacancy complexes in Te-doped GaAs

Gebauer, J.; Lausmann, M.; Staab, T.E.M.; Krause‐Rehberg, R.; Hakala, Mikko; Puska, Martti J.

doi:10.1103/physrevb.60.1464

Cited by 31 publications

(24 citation statements)

References 24 publications

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“…It is interesting to note that the assignment of V Ga in LT-GaAs to defect complexes has some analogies with the presence of donor-Gavacancy complexes in n-doped GaAs. 21,38 Such similarity was also suggested by Hurle in a recent review. 54 Our previous studies show that the V Ga concentration increases with decreasing growth temperature.…”

Section: Discussionsupporting

confidence: 73%

“…21 The annihilation parameters of the complexes are theoretically and experimentally known to be close to the ones of isolated V Ga . 38,41 We must note that av measured at high incident energies in GaAs:Zn and in GaAs:Si is 10-15 ps longer than observed by conventional positron lifetime spectroscopy in the bulk of the same samples. However, the results obtained with the lifetime beam exhibit the same relative changes of av .…”

Section: A Detection Of Vacancies By Doppler Broadening and Positronmentioning

confidence: 87%

“…The theoretical lifetimes are therefore scaled to the experimental bulk lifetime of 229 ps. 38 The density of positively charged As Ga ϩ antisites was determined via the magnetic circular dichroism of absorption ͑MCDA͒ 15 in the samples grown with variable As/Ga flux ratio. Structural investigation of As precipitates in annealed LT-GaAs were performed using a JEOL 4000FX electron microscope operating at 400 kV.…”

Section: ϫ10mentioning

confidence: 99%

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Defect identification in GaAs grown at low temperatures by positron annihilation

Gebauer¹,

Börner

Krause‐Rehberg

et al. 2000

Journal of Applied Physics

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We use positron annihilation to study vacancy defects in GaAs grown at low temperatures ͑LT-GaAs͒. The vacancies in as-grown LT-GaAs can be identified to be Ga monovacancies, V Ga , according to their positron lifetime and annihilation momentum distribution. The charge state of the vacancies is neutral. This is ascribed to the presence of positively charged As Ga ϩ antisite defects in vicinity to the vacancies. Theoretical calculations of the annihilation parameters show that this assignment is consistent with the data. The density of V Ga is related to the growth stoichiometry in LT-GaAs, i.e., it increases with the As/Ga beam equivalent pressure ͑BEP͒ and saturates at 2ϫ10 18 cm Ϫ3 for a BEPу20 and a low growth temperature of 200°C. Annealing at 600°C removes V Ga . Instead, larger vacancy agglomerates with a size of approximately four vacancies are found. It will be shown that these vacancy clusters are associated with the As precipitates formed during annealing.

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Section: Discussionsupporting

confidence: 73%

Section: A Detection Of Vacancies By Doppler Broadening and Positronmentioning

confidence: 87%

Section: ϫ10mentioning

confidence: 99%

See 1 more Smart Citation

Defect identification in GaAs grown at low temperatures by positron annihilation

Gebauer¹,

Börner

Krause‐Rehberg

et al. 2000

Journal of Applied Physics

Self Cite

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show abstract

“…Further identification of the Ga vacancy is obtained from the two-detector coincidence measurements of the Doppler broadening. The behavior of the high-momentum part of the positron-electron distribution is the same in both the LT GaAs and Ga 1ÿx Mn x As layers, and similar as observed previously [19]. The core electron momentum distribution shows the typical signature of As 3d electrons [8,19], indicating directly that the vacancy is in the Ga sublattice.…”

Section: Volume 93 Number 5 P H Y S I C a L R E V I E W L E T T E R supporting

confidence: 63%

“…The behavior of the high-momentum part of the positron-electron distribution is the same in both the LT GaAs and Ga 1ÿx Mn x As layers, and similar as observed previously [19]. The core electron momentum distribution shows the typical signature of As 3d electrons [8,19], indicating directly that the vacancy is in the Ga sublattice. The isolated Ga vacancy, however, is mobile at the growth temperatures of the LT-MBE system [20].…”

Section: Volume 93 Number 5 P H Y S I C a L R E V I E W L E T T E R supporting

confidence: 63%