Enhanced photoluminescence of CaTiO3:Sm3+ red phosphors by Na+, H3BO3 added.

Ca [1−3x/2] TiO 3 :xSm 3+ (0 ≤ x ≤ 5 mol%), Ca 0.955 TiO 3 :0.03Sm 3+ + 10 mol% H 3 BO 3 , Ca 0.94 TiO 3 :0.03Sm 3+ , 0.03Na + phosphors are synthesized by high temperature solid–state reaction method in air. All samples are pure phase CaTiO 3 . Two strong excitation bands within the range 400–435 nm and 455–510 nm are observed, which are nicely match with widely applied near-UV (400–430 nm) and blue (460–500 nm) LED chips. The strongest emission band peaking at ∼603 nm is assigned to the 4 G 5/2 → 6 H 7/2 transition of Sm 3+ ion. The optimal Sm 3+ doping concentration is ∼3 mol%. Fluorescent lifetimes of Ca 0.955 TiO 3 :0.03Sm 3+ phosphor with excitation 408, 467, and 481 nm are ∼0.809 m, 0.792 m, and 0.8 m, respectively. The PL intensity of Ca 0.955 TiO 3 :0.03Sm 3+ phosphor is enhanced 5–7 times after Na + ion is codoped as charge compensator and H 3 BO 3 is added as flux, and their CIE chromaticity coordinate is ∼ (0.5792, 0.4199). The experiment results are helpful to improve luminescence properties of other Sm 3+ -doped phosphors and study novel phosphors. [ABSTRACT FROM AUTHOR]