Luminescence properties of Ce3+ ions in strontium bromoborate

The luminescence properties of Ce3+ ions in strontium bromoborate are reported and discussed. In Sr2(1 - x)Ce2xB5O9Br (x less than or equal to 0.01) solid solutions two principal Ce3+ centers are observed. The dominant center was found to be produced by the direct substitution of the dopant ion for Sr2+ without a local charge compensation. Upon UV excitation this center gives an intense emission with maxima at 326 and 349 nm. The other center is ascribed to an associate of a Ce3+ ion and a cation vacancy. It causes a broad band emission with a maximum at ca. 375 nm. The charge compensation mechanism on the cation sublattice includes the formation of one vacancy per two Ce3+ ions incorporated. Sr2B5O9Br:Ce3+ has potential for use as a storage phosphor for thermal-neutron detection, because of its favorable chemical composition and promising luminescent properties.