Time-resolved luminescence of F and F/sup +/ centers in magnesium oxide

Conference · Wed Jan 01 04:00:00 EST 1986

OSTI ID:5404991

Williams, Jr, G P; Rosenblatt, G H; Tuttle, A E; Williams, R T; Chen, Y

The authors report measurements of the decay of luminescence from F and F+ centers in MgO following excitation by 248-nm excimer laser pulses. The measurements span as many as 9 decades of time and intensity, over a wide range of temperatures above 90/sup 0/K. It is found that in low-hydrogen, thermochemically-reduced MgO, the F and F+ luminescence is emitted predominantly as phosphorescence (200 ns < t < 10 s), implicating charge transfer and trapping which involves the excited states. Furthermore, both the F and F+ luminescence decay curves for t > 200 ns are described by the same time and temperature dependence. This indicates that the same electron traps (probably H/sup -/) govern the decay rates of both bands. Therefore, the F+ center ionizes by electron release to the conduction band (or electron tunneling), as does the F center. This further implies that the F+ and F centers have ground and excited states at closely corresponding energies, and that an F++ center exists in some form between the time of photoionization of the F+ center and its radiative recombination with the de-trapped electron.

• Research Organization: Wake Forest Univ., Winston-Salem, NC (USA); Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5404991
• Report Number(s): CONF-8609138-1; ON: DE86015648
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ALKALINE EARTH METAL COMPOUNDS
CHALCOGENIDES
COLOR CENTERS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELECTROMAGNETIC RADIATION
EMISSION SPECTRA
ENERGY-LEVEL TRANSITIONS
EXCITATION
F CENTERS
IRRADIATION
LASER RADIATION
LUMINESCENCE
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
OXIDES
OXYGEN COMPOUNDS
POINT DEFECTS
PULSED IRRADIATION
RADIATIONS
SPECTRA
TIME DEPENDENCE
VACANCIES