Luminescent properties of blue phosphor BacCaB6O12:Eu2+ under vacuum-ultraviolet and ultraviolet excitation

The luminescence of Eu 2+ in Ba 2 CaB 6 O 12 has been investigated under vacuum ultraviolet and ultraviolet excitation. Two different crystallographic sites are available for Eu 2+ in Ba 2 CaB 6 O 12 . In this structure, there are linear rows of three cations in the order of Ba 2+ , Ca 2+ and Ba 2+ , Ca 2+ being in the central position. The emission spectra of Eu 2+ under vacuum ultraviolet and ultraviolet consist of two broad bands peaking at 445 and 465 nm, which are associated with the f→d transitions of Eu 2+ in the sites of Ba 2+ and Ca 2+ , respectively. Two weak peaks in vacuum ultraviolet range are observed at 160 nm and 200 nm.