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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 18:07 |
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Conference: Bucharest University Faculty of Physics 2016 Meeting
Section: Solid State Physics and Materials Science
Title:
ESR of irradiation point defects in 17O doped and undoped Si-FZ single crystals
Authors:
A. C. JOITA(1,2), S. V. NISTOR(1), I. PINTILIE(1)
Affiliation:
1)National Institute of Materials Physics, Magurele, Ilfov, Romania
2)University of Bucharest, Faculty of Physics, Magurele, Ilfov, Romania
E-mail
alexandra.joita@infim.ro
Keywords:
Abstract:
The upgrade of Large Hadron Collider (LHC) to High Luminosity LHC requires understanding the radiation damage mechanisms responsible for the observed silicon-sensor performance degradation during operation. It is important to understand the radiation damage mechanism in the ultra high purity Si material employed in such detectors, the structure, formation and transformation of the resulting defects with a direct impact on the detector performance.We studied the role of oxygen impurity atoms in the formation and structure of the irradiation paramagnetic point defects (IPPDs) in crystalline silicon used to produce new tracking detectors for HL-LHC. The investigations were performed by electron spin resonance (ESR) spectroscopy (34GHz) from 296K down to 20K on undoped and doped with 17O n-type silicon (FZ-Wacker) irradiated at doses of 3.5MeV electrons. New anisotropic ESR spectra were observed during in-situ optical excitation at different temperatures. Further changes took place after thermal annealing from 1500C up to 3000C in steps of 50 degrees. The ESR spectra recorded at low and high microwave power levels, with the magnetic field in a (110) plane, where quantitatively analyzed and resulted in the identification of several IPPDs, characterized by different spin Hamiltonian parameters and local symmetry. The structural models of the resulting IPPDs are used to explain the changes in the ESR spectra of the samples.
References:
[1] R. Radu, E. Fretwurst, R. Klanner, G. Lindstroem, I. Pintilie, Nucl. Instrum. & Meth. Phys. Res. A730, 84 (2013);
[2] S. V. Nistor, D. Ghica, I. Pintilie, E. Manaila, Rom. Repts. Phys. 65, 812 (2013).
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