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

Abstract

Ca[1−3x/2]TiO3:xSm3+ (0 ≤ x ≤ 5 mol%), Ca0.955TiO3:0.03Sm3+ + 10 mol% H3BO3, Ca0.94TiO3:0.03Sm3+, 0.03Na+ phosphors are synthesized by high temperature solid–state reaction method in air. All samples are pure phase CaTiO3. 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 4G5/2 → 6H7/2 transition of Sm3+ ion. The optimal Sm3+ doping concentration is ∼3 mol%. Fluorescent lifetimes of Ca0.955TiO3:0.03Sm3+ phosphor with excitation 408, 467, and 481 nm are ∼0.809 m, 0.792 m, and 0.8 m, respectively. The PL intensity of Ca0.955TiO3:0.03Sm3+ phosphor is enhanced 5–7 times after Na+ ion is codoped as charge compensator and H3BO3 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 Sm3+-doped phosphors and study novel phosphors.