A Highly Efficient White Light (Sr3,Ca,Ba)(PO4)3Cl:Eu2+, Tb3+, Mn2+ Phosphor via Dual Energy Transfers for White Light-Emitting Diodes
文摘
A series of single-phased (Sr3鈥?i>x,Ca1鈥?i>y鈥?i>z,Ba)(PO4)3Cl (SCBPO_Cl):xEu2+, yTb3+, zMn2+ phosphors were synthesized by high-temperature solid-state reaction, and luminescent properties of these phosphors were investigated by means of photoluminescence and microcathode luminescence (渭-CL). Under UV excitation, white-light emission was obtained from triactivated SCBPO_Cl phosphors via combining three emission bands centered at 450, 543, and 570 nm contributed by Eu2+, Tb3+, and Mn2+, respectively. White-light emission with the three emission bands is further demonstrated in the fluorescence microscope images, CL spectrum, and 渭-CL mappings, which strongly confirm that the luminescence distribution of as-prepared SCBPO_Cl:xEu2+, yTb3+, zMn2+ phosphors is very homogeneous. Both spectral overlapping and lifetime decay analyses suggest that dual energy transfers, that is, Eu2+鈫扵b3+ and Eu2+鈫扢n2+, play key roles in obtaining the white emission. The International Commission on Illumination value of white emission as well as luminescence quantum yield (51.2鈥?1.4%) can be tuned by precisely controlling the content of Eu2+, Tb3+, and Mn2+. These results suggest that this single-phased SCBPO_Cl:xEu2+, yTb3+, zMn2+ phosphor may have a potential application as a near-UV convertible white-light emission phosphor for phosphor-converted white light-emitting diode.