Luminescence properties of Sm3+ and Dy3+ co-doped BaY2ZnO5 phosphor for white LED

Single-phased warm-white-emitting BaY2ZnO5:Dy3+,Sm3+ phosphors were synthesized by a high-temperature solid state reaction method. The crystal structure, luminescence properties, decay lifetimes, thermal stability and internal quantum efficiency (IQE) were investigated. Under 354 nm excitation, the emission spectrum exhibits the characteristic transitions of Sm3+ and Dy3+. Concentration quenching of Sm3+ and energy transfer mechanism are determined to be the dipole-dipole interactions. Due to the energy transfer from Dy3+ to Sm3+, the color tones and correlated color temperature (CCT) can be changed from near cool-white to warm-white when adjusting Sm3+ concentrations. The optimal BaY2ZnO5: 0.14Dy(3+), 0.04Sm(3+) emits warm-white light with CIE coordinates of (0.404, 0.367), low CCT of 3337 K, activation energy of 0.2389 eV and IQE of 61.5%, making it as a promising candidate white-emitting phosphor for LEDs application.