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

The photoluminescence (PL) properties of the Ba1−0.5xSr1−0.5xAl2SiO7:xM (0.01 ≤ x ≤ 0.04: M = Eu2+ and Dy3+), and Ba0.985−0.5ySr0.985−0.5yAl2SiO7:0.03Eu2+, 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 Ba0.985−0.5ySr0.985−0.5yAl2SiO7:0.03Eu2+, 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 Ba0.985−0.5ySr0.985−0.5yAl2SiO7:0.03Eu2+, yDy3+ (0.01 ≤ y ≤ 0.03) phosphors produced much stronger luminescence, ∼350% higher than that of the Ba0.985Sr0.985Al2SiO7:0.03Eu2+ phosphor.