Influence of Dy3+ co-doping on the luminescence properties of bluish-green Ba1−0.5ySr1−0.5yAl2SiO7:yEu2+ phosphors

Abstract

The photoluminescence (PL) properties of the Ba_1−0.5xSr_1−0.5xAl₂SiO₇:xM (0.01 ≤ x ≤ 0.04: M = Eu²⁺ and Dy³⁺), and Ba_0.985−0.5ySr_0.985−0.5yAl₂SiO₇:0.03Eu²⁺, yDy³⁺ (0.01 ≤ y ≤ 0.03) phosphors are studied. The excitation spectra of the co-doped phosphors exhibit an asymmetric broad band in the 250 to 450 nm range, attributed to the transitions of Eu²⁺ (4f⁷ → 4f⁶5d¹). Upon 330 nm excitation, the Ba_0.985−0.5ySr_0.985−0.5yAl₂SiO₇:0.03Eu²⁺, yDy³⁺ (0.01 ≤ y ≤ 0.03) phosphors emit bluish-green emission in the 400–750 nm range, arising from the 4f⁶5d¹ → 4f⁷ transition of Eu²⁺. It was found that the Ba_0.985−0.5ySr_0.985−0.5yAl₂SiO₇:0.03Eu²⁺, yDy³⁺ (0.01 ≤ y ≤ 0.03) phosphors produced much stronger luminescence, ∼350% higher than that of the Ba_0.985Sr_0.985Al₂SiO₇:0.03Eu²⁺ phosphor.