Photoconversion of {ital F}-type centers in thermochemically reduced MgO single crystals
- Departamento de Fisica, Escuela Politecnica Superior, Universidad Carlos III, Butarque 15, 28911 Leganes, Madrid (Spain)
- Division of Materials Science, Department of Energy, Germantown, Maryland 20874-1290 (United States)
- Institute for Solid State Physics, University of Latvia, 8 Kengaraga, LV-1063 Riga (Latvia)
Optical absorption and luminescence experiments were used to study the photoconversion of neutral oxygen vacancies ({ital F} centers) in MgO single crystals thermochemically reduced at elevated temperatures. In crystals with an undetectable concentration of hydride ions and a moderate concentration of {ital F} centers ({approx}10{sup 17} cm{sup {minus}3}), excitation with UV-light produces positively charged anion vacancies (F{sup +} centers) and electrons which are subsequently trapped at impurities. Under continuous excitation, the F{sup +} centers release holes which are trapped at cation vacancies charge compensated by impurities. In crystals with high concentrations of both hydride ions and {ital F} centers ({approx}10{sup 18} cm{sup {minus}3}), the electrons from the {ital F} to F{sup +} photoconversion are trapped mainly at the hydride ions to form H{sup 2{minus}} ions, which are metastable at room temperature. {copyright} {ital 1999} {ital The American Physical Society}
- OSTI ID:
- 306262
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 59, Issue 7; Other Information: PBD: Feb 1999
- Country of Publication:
- United States
- Language:
- English
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