Synthesis and photoluminescence of novel blue‐emitting phosphor of Eu 2+ ‐activated fluoroborate BaGaBO 3 F 2

Pure and Eu 2+ ‐activated fluoroborate BaGaBO 3 F 2 was prepared using high‐temperature solid‐state reaction. BaGaBO 3 F 2 is a wide band semiconductor with the indirect transition characteristic. The excitation and luminescence spectra of the phosphor were measured, and it was found that Eu 2+ ‐activated BaGaBO 3 F 2 exhibits a bright blue color under ultraviolet (UV) light. The narrow emission band peaked at 425 nm is attributed to the transitions of 4f 6 5d→4f 7 ( 8 S 7/2 ), and the Stokes shift estimated for this phosphor sample is 3140 cm −1 . The lifetime of the luminescence is also reported. The absolute quantum efficiency (QE) of the phosphor was evaluated, and it was found that the absolute QE decreases with increasing Eu 2+ concentration. The phosphor shows an excellent quantum efficiency of 72.5% and a high thermal activation energy of 0.342 eV. The study concludes that Eu 2+ ‐doped BaGaBO 3 F 2 phosphor has promising luminescence application abilities and can be used as a blue‐emitting phosphor in a variety of applications.