Defect Network in Superconducting Ceramic Oxides Studied by Neutron and Proton Irradiation

1990 ◽  
Vol 209 ◽  
Author(s):  
E. Mezzetti ◽  
D. Andreone ◽  
G. Castagno ◽  
R. Cherubini ◽  
S. Colombo ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Proton Irradiation ◽  
Short Circuit ◽  
Oxide Ceramics ◽  
High Fluence ◽  
Ceramic Oxides ◽  
Radiation Induced ◽  
Proton Implantation ◽  
Induced Defects ◽  
Superconducting Ceramic

ABSTRACTThis paper investigates both transport properties and nature of superconductivity breakdown or, conversely, enhancement in oxide ceramics, due to radiation-induced defects.Low-fluence neutrons (≈107 n cm-2 at 3 MeV) can sensitively damage the samples, giving experimental evidence that the breakdown of coherent percolating paths produces decoupled domains. A set of preliminary measurements shows that high-fluence proton implantation can either damage or enhance critical current density in a currently non controllable way. In both cases strongly damaged or enhanced superconducting paths short-circuit the unaffected bulk network.

Effect of Proton Irradiation Induced Defects on 4H-SiC Schottky Diode X-Ray Detectors

2011 ◽  
Vol 679-680 ◽  
pp. 547-550
Author(s):  
Rupert C. Stevens ◽  
Konstantin Vassilevski ◽  
John E. Lees ◽  
Nicolas G. Wright ◽  
Alton B. Horsfall
Keyword(s):  
Schottky Diode ◽  
Nuclear Power ◽  
Proton Irradiation ◽  
Deep Level ◽  
High Dose ◽  
X Ray ◽  
Power Stations ◽  
Radiation Induced ◽  
Transient Spectroscopy ◽  
Induced Defects

Detectors capable of withstanding high radiation environments for prolonged periods of exposure are essential for the monitoring of nuclear power stations and nuclear waste as well as for space exploration. Schottky diode X-ray detectors were exposed to high dose proton irradiation (1013 cm-2, 50 MeV) and changes in the detection resolution (spectroscopic full width half-maximum) have been observed. Using Deep Level Transient Spectroscopy (DLTS) and the degradation of the electrical characteristics of the diode, we have shown that radiation induced traps located in the upper half of the bandgap have reduced the concentration of carriers.

Proton Irradiation Induced Defects in 611- and 4H-SiC

1998 ◽  
Vol 540 ◽  
Author(s):  
Werner Puff ◽  
Adam G. Balogh ◽  
Peter Mascher
Keyword(s):  
Proton Irradiation ◽  
Positron Lifetime ◽  
Doppler Broadening ◽  
Defect Complexes ◽  
Radiation Induced ◽  
Positron Lifetime Spectroscopy ◽  
Induced Defects ◽  
Irradiation Induced Defects ◽  
Type Sample

AbstractAnnealing of defects in proton irradiated bulk n-type 6H- and semi-insulating 4H-SiC has been investigated by positron lifetime spectroscopy and Doppler-broadening measurements. For the n-type sample radiation induced defects in dependence of the proton fluence were studied. Three or four annealing stages were found, during which the formation of larger defect complexes could be observed.

Radiation-Induced Defects in Electron and Proton Irradiated ZnS

1998 ◽  
Vol 540 ◽  
Author(s):  
S. Brunner ◽  
W. Puff ◽  
P. Mascher ◽  
A.G. Balogh
Keyword(s):  
Vapour Deposition ◽  
Proton Irradiation ◽  
Positron Lifetime ◽  
Chemical Vapour ◽  
Isochronal Annealing ◽  
Doppler Broadening ◽  
Defect Complexes ◽  
Radiation Induced ◽  
The Stability ◽  
Induced Defects

AbstractIn this contribution, we present a study aimed at investigating the microstructural changes of ZnS single crystals and CVD (chemical vapour deposition) grown crystals after electron and proton irradiation. Positron lifetime and Doppler-broadening measurements were performed to investigate the stability of the radiation induced defects and possible clustering mechanisms during isochronal annealing. After electron as well as proton irradiation the significant changes in the annihilation characteristics are indications of radiation induced open-volume-type defects. It is found that electron and proton irradiation causes different changes in the positron annihilation characteristics. After electron irradiation a significant defect component is observed which can be attributed to the annihilation in monovacancies. During isochronal annealing agglomerations to divacancy-type defects take place. Proton irradiation reveals a significantly different defect structure. Isochronal annealing causes agglomerations to larger defect complexes. The observed annealing stages are indications of the annealing of variously sized vacancy complexes.

Radiation-Induced Defects in Si after High Dose Proton Irradiation

2017 ◽  
Vol 373 ◽  
pp. 209-212 ◽  
Author(s):  
Yurii V. Funtikov ◽  
Leonid Yu. Dubov ◽  
Yurii V. Shtotsky ◽  
Sergey V. Stepanov
Keyword(s):  
Bragg Peak ◽  
Proton Irradiation ◽  
Defect Formation ◽  
High Energy ◽  
High Dose ◽  
Number Density ◽  
High Energy Proton ◽  
Energy Proton ◽  
Radiation Induced ◽  
Induced Defects

Experiments on investigation of the radiation defects produced as a result of high energy proton irradiation of single crystal Si wafers are carried out. Parameters of the proton irradiation facility are presented. It is shown that the most efficient radiation defect formation correlates with the position of the Bragg peak of ionization losses. LT spectra were measured just after irradiation and then after keeping Si samples during 3 months of at room T. We did not observe any variation of the number density of the defects, except for the 7th wafer, where most part of protons was stopped. An efficient annealing of the vacancy-type defects starts at temperatures slightly lower than 100 °C (during 10 min). Annealing at about 700 °C leads to recovering of the monoexponrntial shape of the LT spectra.

Microstructural Evolution of Radiation Induced Defects In ZnO During Isochronal Annealing

1998 ◽  
Vol 540 ◽  
Author(s):  
S. Brunner ◽  
W. Puff ◽  
P. Mascher ◽  
A.G. Balogh
Keyword(s):  
Room Temperature ◽  
Proton Irradiation ◽  
Positron Lifetime ◽  
Thermal Evolution ◽  
Isochronal Annealing ◽  
Doppler Broadening ◽  
Thermal Dependence ◽  
Radiation Induced ◽  
Induced Defects ◽  
Mev Protons

AbstractIn this study we discuss the microstructural changes after electron and proton irradiation and the thermal evolution of the radiation induced defects during isochronal annealing. The nominally undoped samples were irradiated either with 3 MeV protons to a fluence of 1.2× 1018 p/cm2 or with 1 MeV electrons to a fluence of 1×1018 e/cm2. The investigation was performed with positron lifetime and Doppler-broadening measurements. The measurements were done at room temperature and in some cases down to 10 K to investigate the thermal dependence of the trapping characteristics of the positrons.

Proton Irradiation Damage in Zn and Cd Doped InP

1993 ◽  
Vol 325 ◽  
Author(s):  
George C. Rybicki ◽  
Wendell S. Williams
Keyword(s):  
Cross Sections ◽  
Deep Level Transient Spectroscopy ◽  
Proton Irradiation ◽  
Deep Level ◽  
Irradiation Damage ◽  
Radiation Induced ◽  
Diffusion Rates ◽  
Transient Spectroscopy ◽  
Induced Defects ◽  
Capture Cross Sections

AbstractDeep Level Transient Spectroscopy (DLTS) was used to study the defects introduced in Zn and Cd doped Schottky barrier diodes by 2 MeV proton irradiation. The defects H3, H4 and H5 were observed in lightly Zn doped InP, while only the defects H3 and H5 were observed in more heavily Zn doped and Cd doped InP. The defect activation energies and capture cross sections did not vary between the Zn and Cd doped InP.The concentration of the radiation induced defects was also measured. The introduction rate of the defect H4 in the lightly Zn doped InP and the introduction rate of the defect H3 in the heavily Zn and Cd doped InP were about equal, but the introduction rate of the defect H5 varied strongly among the three types of material. The introduction rate of H5 was highest in the heavily Zn doped InP but the lowest in the heavily Cd doped InP, even though they were doped comparably. As a result, the total defect introduction rate was lowest in the highly Cd doped InP.The results can be interpreted in terms of the models for the formation and annealing of defects, and by the different diffusion rates of Zn and Cd in InP.

High-Energy Electron and Proton Irradiation of Cu(In,Ga)Se2 Heterojunction Solar Cells

2001 ◽  
Vol 668 ◽  
Author(s):  
A. Jasenek ◽  
A. Boden ◽  
K. Weinert ◽  
M. R. Balboul ◽  
H. W. Schock ◽  
...  
Keyword(s):  
Solar Cells ◽  
Proton Irradiation ◽  
High Efficiency ◽  
High Energy ◽  
Open Circuit ◽  
Solar Cell Efficiency ◽  
Heterojunction Solar Cells ◽  
Cell Efficiency ◽  
Radiation Induced ◽  
Induced Defects

ABSTRACTWe investigate radiation-induced defects in high-efficiency Cu(In,Ga)Se2/CdS/ZnO heterojunction solar cells after 1-MeV electron and 4-MeV proton irradiation. We use electron and proton fluences of more than 1018 cm−2 and up to 1014 cm−2, respectively. The irradiation experiments performed at three independent electron irradiation facilities consistently prove the superior radiation resistance of these Cu(In,Ga)Se2 devices compared to other types of solar cells. The reduction of the solar cell efficiency in all experiments is predominantly caused by a loss ΔVOC of the open circuit voltage VOC. An analytical model describes ΔVOC in terms of radiation-induced defects enhancing recombination in the Cu(In,Ga)Se2 absorber material. From our model we extract the defect introduction rates for recombination centers in Cu(In,Ga)Se2 for the respective particles and energies. Isochronal annealing steps fully recover VOC of the irradiated Cu(In,Ga)Se2 solar cells. Exposure to temperatures of approx. 400 K are sufficient to restore the initial VOC within less than 5 %, even after excessive irradiation. The annealing process displays an activation energy of EA = 1.1 eV. Admittance spectroscopy directly reveals the generation and the annealing of radiation-induced defects.

Vacancy-Type Defects in Electron and Proton Irradiated II- VI Compounds

1996 ◽  
Vol 439 ◽  
Author(s):  
S. Brunner ◽  
W. Puff ◽  
P. Mascher ◽  
A. G. Balogh ◽  
H. Baumann
Keyword(s):  
Positron Annihilation ◽  
Proton Irradiation ◽  
Basic Properties ◽  
Radiation Induced ◽  
Induced Defects ◽  
Mev Protons

AbstractIn this contribution, we present a study aimed at investigating the basic properties of radiation induced defects in ZnS and ZnO and the influence of the atmosphere on the annealing characteristics of the defects. Positron annihilation experiments (both lifetime and Dopplerbroadening measurements) were performed on both single- and polycrystalline samples, irradiated with 3 MeV protons or 1 MeV electrons. For ZnS it was found that both electron and proton irradiation caused significant changes in the positron annihilation characteristics. The annealing of proton irradiated ZnS in air leads to significant oxidation and eventual transformation into ZnO.

Analysis of Proton Induced Defects in Cu(In,Ga)Se2 Thin-Film Solar Cells

2005 ◽  
Vol 865 ◽  
Author(s):  
Shirou Kawakita ◽  
Mitsuru Imaizumi ◽  
Koichi Kibe ◽  
Shinichi Yoda ◽  
Takeshi Ohshima ◽  
...  
Keyword(s):  
Solar Cells ◽  
Spectral Response ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Minority Carrier Diffusion Length ◽  
Defect Annealing ◽  
Radiation Induced ◽  
Cigs Solar Cells ◽  
Induced Defects ◽  
Mev Protons

AbstractWe investigated radiation-induced defects in CIGS solar cells with a solar-cell simulator to analyze the spectral response of the irradiated cells. The damage constant of the minority-carrier diffusion length of the cells irradiated with 1 MeV protons was determined to be 3.5 ×10-5. This analysis led to the relation between the defect introduction rate and proton energy, and was obtained using the same method, as was the defect annealing rate. This result agreed well with that estimated from an analysis of changes in short-circuit current degradation.

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