Effects of methane annealing ambience on the structure and photoluminescence of BCNO phosphors

Green-emitting BCNO phosphors are synthetized by low temperature liquid method. And then the properties of structure and photoluminescence of BCNO phosphors annealed under methane ambience at 500-700 °C for 4 h and at 600 °C for 3-6 h are researched. When the phosphor was annealed for the same time period, the crystallinity was improved first and then became poor as the annealing temperature increased. In addition, the emission peak shifted to high wavelength, and the maximum shift span reached up to 40 nm. When the phosphor was annealed at the same temperature, the crystallinity was improved and the emission peak was red-shifted. The multi-peaks fitting results indicated that three luminescence mechanisms which were C-related defect, B-O luminescence center and other defects or vacancies played important roles in BCNO phosphors.