Synthesis and photoluminescence properties of Eu(3+)-activated LiCa(3)ZnV(3)O(12) white-emitting phosphors

Single-component white-emitting phosphors are highly promising for applications in phosphor-converted white light-emitting diodes. In this paper, novel single-phase LiCa(3(1−x))ZnV(3)O(12):Eu(3+) (x = 0–0.05) phosphors with tunable white emissions were prepared by a conventional solid-state reaction. The LiCa(3)ZnV(3)O(12) (x = 0) phosphor showed an efficient self-activated bluish-green emission due to the V(5+)–O(2−) charge transfer transition of the [VO(4)](3−) groups, and possessed an intense broad excitation spectrum in the 250–400 nm wavelength range. Together with the [VO(4)](3−) emission, the red emission of Eu(3+) ions was also observed in LiCa(3(1−x))ZnV(3)O(12):Eu(3+) phosphors. The energy transfer from the [VO(4)](3−) groups to the Eu(3+) ions was studied. Importantly, the emission colors of LiCa(3(1−x))ZnV(3)O(12):Eu(3+) phosphors varied from greenish-blue to whitish and then to red with increasing Eu(3+) content and the white-light emission was realized in the single-phase phosphor of LiCa(3)ZnV(3)O(12):0.003Eu(3+) by combining the [VO(4)](3−)-emission and the Eu(3+)-emission. The energy-transfer efficiency from [VO(4)](3−) groups to Eu(3+) ions in the LiCa(3)ZnV(3)O(12):0.003Eu(3+) sample was determined to be about 52% and the internal quantum efficiency of the LiCa(3)ZnV(3)O(12):0.003Eu(3+) phosphor was found to be about 41.5%. In addition, the CIE chromaticity coordinates of LiCa(3)ZnV(3)O(12):0.003Eu(3+) were (x = 0.3374, y = 0.3596), and the correlated color temperature was estimated to be about 5311 K.