Abstract
Optical characterization of Ba_3Si_6O_<12>N_2Eu^<2+> (BSON) phosphor was carried out based on an internal quantum efficiency, photoluminescence (PL), and thermoluminescence (TL) measurements. Carrier trapping levels were detected by TL spectra, and thermal activation energy of each was determined by the relation between peak position and temperature gradient. An atmospheric annealing of the BSON phosphor increased the density of a carrier trapping level which corresponds to the secondary TL peak, and decreased the internal quantum efficiency. On the other hand, an annealing in a hydrogen atmosphere brought no increase in the density of the carrier trapping level, keeping high value of internal quantum efficiency.
