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Title: Cascade phonon-assisted trapping of positrons by divacancies in n-FZ-Si(P) single crystals irradiated with 15 MeV protons

The trapping of positrons by the radiation defects in moderately doped oxygen-lean n-FZ-Si(P) single crystal irradiated with 15 MeV protons has been investigated in a comparative way using the positron lifetime spectroscopy and Hall effect measurements. The experiments were carried out within a wide temperature interval ranging from 25 K – 29 K to 300 K. The positron trapping rate for divacancies was reconstructed in the course of many-stage isochronal annealing. The concentration and the charged states of divacancies (V{sub 2}{sup −} and V{sub 2}{sup −−}) were estimated. The temperature dependency of the trapping cross section of positrons by the negatively charged divacancies is in a good agreement with the data of calculations based on the assumptions of the cascade phonon-assisted mechanism of exchange of the energy between the positron and acoustic long-wave phonons. Obeying ∼ T{sup −3} law, the cross-section of the trapping of positrons by divacancies changes considerably ranging from ∼1.7×10{sup −12} cm{sup 2} (66 – 100 K) to ∼2×10{sup −14} cm{sup 2} (≈ 250 K). The characteristic length of trapping of the positron by V{sub 2}{sup −−} divacancy was estimated to be l{sub 0}(V{sub 2}{sup −−})≈(3.4±0.2)×10{sup −8} cm.
Authors:
 [1] ; ;  [2] ; ;  [3] ;  [4] ;  [5]
  1. Martin Luther University Halle, Department of Physics, 06120 Halle, Germany and Inst. of Ion-Plasma and Laser Technologies (Inst. of Electronics), 700187 Tashkent (Uzbekistan)
  2. Ioffe Physico-Technical Institute, 194021 St. Petersburg (Russian Federation)
  3. Martin Luther University Halle, Department of Physics, 06120 Halle (Germany)
  4. Martin Luther University Halle, Department of Physics, 06120 Halle, Germany and Minia university, Faculty of Science, Physics Department, P.O. box 61519 Minia (Egypt)
  5. St. Petersburg State Polytechnic University, 195251 St. Petersburg (Russian Federation)
Publication Date:
OSTI Identifier:
22263718
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1583; Journal Issue: 1; Conference: ICDS-2013: 27. international conference on defects in semiconductors, Bologna (Italy), 21-26 Jul 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANNEALING; CROSS SECTIONS; DOPED MATERIALS; HALL EFFECT; IRRADIATION; MONOCRYSTALS; PHONONS; POSITRONS; PROTONS; SPECTROSCOPY