Infrared absorption studies of the divacancy in silicon: New properties of the singly negative charge state

Journal Article · Mon Aug 15 04:00:00 EDT 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.38.4192· OSTI ID:6862528

Svensson, J H; Svensson, B G; Monemar, B

The infrared optical absorption peak at 0.34 eV in silicon, which is usually associated with the singly negative charge state of the divacancy, has been investigated in electron-irradiated samples with use of different optical excitation conditions. It is proposed that a strong Jahn-Teller distortion makes it possible to populate this charge state, when the defect initially is in the neutral charge state, either by the capture of a photoexcited free electron from the conduction band, or by the direct photoexcitation of an electron from the valence band to a defect orbital. Experimental evidence for the existence of these reactions is presented. A defect level at E/sub c/-0.54 eV, frequently associated with the singly negative charge state of the divacancy, is identified as one of the levels from which these photoexcited free electrons originate. The 0.34-eV peak is attributed to an internal transition in the singly negative charge state of the divacancy center, implying the existence of a shallow defect state at approximately E/sub c/-0.07 eV for this charge state. Experimental support is given for the existence of this shallow state. A tentative explanation, based on the strong Jahn-Teller distortion of the singly negative charge state, is suggested for the fact that the doubly negative charge state is not observed at temperatures below 90 K.

• Research Organization: Department of Physics and Measurement Technology, Linkoeping University, S-581chemically bond83 Linkoeping, Sweden
• OSTI ID: 6862528
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 38:6; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360605* -- Materials-- Radiation Effects
ABSORPTION SPECTRA
ANIONS
CHARGE STATES
CHARGED PARTICLES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELECTROMAGNETIC RADIATION
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
GAMMA RADIATION
INFRARED SPECTRA
IONIZING RADIATIONS
IONS
LEPTONS
PHYSICAL RADIATION EFFECTS
POINT DEFECTS
RADIATION EFFECTS
RADIATIONS
SEMIMETALS
SILICON
SPECTRA
VACANCIES