Positron spectroscopy of bulk and near-surface defects in semiconductors

1989 ◽  
Vol 67 (8) ◽  
pp. 813-817
Author(s):  
P. Hautojārvi
Keyword(s):  
Positron Annihilation ◽  
Positron Lifetime ◽  
Surface Defects ◽  
Positron Beam ◽  
Near Surface ◽  
Slow Positron ◽  
Positron Spectroscopy ◽  
Positron Lifetime Spectroscopy ◽  
Defects In Semiconductors ◽  
Ion Implanted

The use of positron annihilation to study defects in semiconductors is discussed. Positron-lifetime spectroscopy reveals As vacancies in as-grown GaAs and gives information on ionization levels. The vacancy profiles in ion-implanted Si are investigated by slow positron beam.

scholarly journals A new approach to near-surface positron annihilation analysis of ion irradiated ferritic alloys

2021 ◽  
Author(s):  
Vladimir Krsjak ◽  
Petr Hruška ◽  
Jarmila Degmova ◽  
Stanislav Sojak ◽  
Pavol Noga ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Ion Beam ◽  
Positron Beam ◽  
Ion Beam Irradiation ◽  
Near Surface ◽  
Slow Positron ◽  
New Approach ◽  
Ferritic Alloys ◽  
Positron Annihilation Lifetime ◽  
Variable Energy

The present work provides an innovative approach to the near-surface slow-positron-beam (SPB) study of structural materials exposed to ion-beam irradiation. This approach enables the use of variable-energy positron annihilation lifetime...

Investigation of Near Surface Defects by Variable-Energy Positron Lifetime Spectroscopy

1992 ◽  
Vol 105-110 ◽  
pp. 1459-1462 ◽  
Author(s):  
Ryoichi Suzuki ◽  
Yoshinori Kobayashi ◽  
Tomohisa Mikado ◽  
Hideaki Ohgaki ◽  
M. Chiwaki ◽  
...  
Keyword(s):  
Positron Lifetime ◽  
Surface Defects ◽  
Near Surface ◽  
Positron Lifetime Spectroscopy ◽  
Variable Energy

scholarly journals On the Limitations of Positron Annihilation Spectroscopy in the Investigation of Ion-Implanted FeCr Samples

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1689
Author(s):  
Vladimir Slugen ◽  
Jarmila Degmova ◽  
Stanislav Sojak ◽  
Martin Petriska ◽  
Pavol Noga ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Positron Annihilation ◽  
Neutron Irradiation ◽  
Surface Region ◽  
Positron Beam ◽  
Positron Annihilation Spectroscopy ◽  
Radiation Embrittlement ◽  
Nuclear Facilities ◽  
Near Surface ◽  
Slow Positron

New materials for advanced fission/fusion nuclear facilities must inevitably demonstrate resistance to radiation embrittlement. Thermal and radiation ageing accompanied by stress corrosion cracking are dominant effects that limit the operational condition and safe lifetime of the newest nuclear facilities. To study these phenomena and improve the current understanding of various aspects of radiation embrittlement, ion bombardment experiments are widely used as a surrogate for neutron irradiation. While avoiding the induced activity, typical for neutron-irradiated samples, is a clear benefit of the ion implantation, the shallow near-surface region of the modified materials may be a complication to the post-irradiation examination (PIE). However, microstructural defects induced by ion implantation can be effectively investigated using various spectroscopic techniques, including slow-positron beam spectroscopy. This method, typically represented by techniques of positron annihilation lifetime spectroscopy and Doppler broadening spectroscopy, enables a unique depth-profile characterisation of the near-surface region affected by ion bombardment or corrosion degradation. One of the best slow-positron beam facilities is available at the pulsed low-energy positron system (PLEPS), operated at FRM-II reactor in Munich (Germany). Bulk studies (such as high energy ion implantation or neutron irradiation experiments) can be, on the other hand, effectively performed using radioisotope positron sources. In this paper, we outline some basics of the two approaches and provide some recommendations to improve the validity of the positron annihilation spectroscopy (PAS) data obtained on ion-irradiated samples using a conventional 22Na positron source.

Reemitted positron spectroscopy of near-surface defects

1990 ◽  
Vol 42 (4) ◽  
pp. 1910-1916 ◽  
Author(s):  
T. McMullen ◽  
M. J. Stott
Keyword(s):  
Surface Defects ◽  
Near Surface ◽  
Positron Spectroscopy

Near-surface defects in hydrogen-plasma-treated boron-doped silicon studied by positron beam spectroscopy

1999 ◽  
Vol 68 (6) ◽  
pp. 643-645 ◽  
Author(s):  
C.E. Gonzalez ◽  
S.C. Sharma ◽  
N. Hozhabri ◽  
D.Z. Chi ◽  
S. Ashok
Keyword(s):  
Surface Defects ◽  
Hydrogen Plasma ◽  
Positron Beam ◽  
Near Surface ◽  
Boron Doped ◽  
Doped Silicon

Defects Distribution of Pr2Fe14B Hard Magnetic Magnet from Amorphous to Nanostructures Characterized by Positron Annihilation Spectroscopy

2005 ◽  
Vol 475-479 ◽  
pp. 2123-2126
Author(s):  
Yu Cheng Wu ◽  
W. Sprengel ◽  
K. Reimann ◽  
K.J. Reichle ◽  
D. Goll ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Grain Growth ◽  
Melt Spinning ◽  
Positron Lifetime ◽  
Positron Annihilation Spectroscopy ◽  
Amorphous Structure ◽  
Defect Distribution ◽  
Positron Lifetime Spectroscopy ◽  
Positron Lifetimes ◽  
Shape And Size

The defect distributions have been investigated using positron lifetime spectroscopy on amorphous and nanocrystalline Pr2Fe14B samples, produced by melt-spinning and nanocrystallization route. The main two components can be concluded that were ascribed to vacancy-like defects in the intergranular layers or the interfaces, and microvoids or large free volumes with size compared to several missing atoms at the interactions of the atomic aggregates or the crystallites. The remarkable changes in the positron lifetimes from the amorphous structure to the nanocrystalline with varied sizes can be interpreted, indicating that the structural transformation and the grain growth induce the defect distribution changes occurring at the interfaces with different shape and size.

scholarly journals Study of Microvoids in High-Rate a-Si:H Using Positron Annihilation

1997 ◽  
Vol 467 ◽  
Author(s):  
X. Zou ◽  
D. P. Webb ◽  
S. H. Lin ◽  
Y. W. Lam ◽  
Y. C. Chan ◽  
...  
Keyword(s):  
Thin Films ◽  
Positron Annihilation ◽  
Surface Region ◽  
Positron Beam ◽  
High Rate ◽  
Doppler Broadening ◽  
Slow Positron ◽  
Depth Profiles ◽  
Vacancy Type Defect ◽  
Low Rate

ABSTRACTIn this paper, we have carried out the positron annihilation measurement on high-rate and low-rate a-Si:H thin films deposited by PECVD. By means of the slow positron beam Doppler-broadening technique, the depth profiles of microvoids in a-Si:H have been determined. We have also studied the vacancy-type defect in the surface region in high-rate grown a-Si:H, making comparison between high-rate and low-rate a-Si:H. By plotting S and W parameters in the (S, W) plane, we have shown that the vacancies in all of the high-rate and low-rate deposited intrinsic samples, and in differently doped low-rate samples are of the same nature.

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