Ca掺杂的Ba_2Al_2Si_(10)N_(14)O_4:Eu^(2+)荧光粉发光性能

Luminescence Properties of Ca Doped Ba_2Al_2Si_(10)N_(14)O_4∶Eu^(2+) Phosphor

通过固相反应制备了系列Ca掺杂的Ba2Al2Si10N14O4∶Eu2+绿色荧光粉,发现当半径较大的Ba被Ca取代后导致了晶格的收缩,通过X射线衍射(XRD)测量和Unitcell软件计算发现Ca的最大掺杂量在20%。Ca掺入Eu0.4Ba1.6Al2Si10N14O4荧光粉后,可有效地提高光转换性能,并使激发光谱发生一定程度的红移和宽化,从而被近紫外宽波段光有效激发,与近紫外LED的发射光谱匹配。同时Ca的掺杂也使发射光谱发生了可控的红移,可以由520 nm的绿光红移至548 nm的黄光区域。进一步发现Eu2+的淬灭浓度随着20%Ca的掺入而降低,这是由于Ca掺入导致的晶格收缩使Eu2+离子间距离减小。最后在CIE色度图中对不同Ca,Eu浓度的荧光粉的色坐标位置进行比较,发现可通过Ca,Eu浓度的变化在很大范围内调制荧光粉的发光性能。

The Ca doped BazAl2Si10N14O4：Eu2＋ phosphors were prepared by a solid-state reaction method. From XRD results, only the single-phase region was found under 20% Ca content. Based on parameters calculated by Unitcell, the crystal lattice shrinks after the Ca incorporation because of the smaller radius of Ca2＋. The photoluminescence （PL） properties of Ca doped Ba2A12Si10N14O4：Eu2＋ phosphors were investigated. The excitation spectra cover the UV- Visible spectral region from 250-400 nm. The red shifts of excitation and emission spectra are from 300 nm to 320 nm and 520 nm to 548 nm, respectively. The emission intensity and wavelength of Ca doped Ba2Al2Si10N14O4：Eu2＋ phosphors as a function of Eu2 ＋ concentration were also studied. The CIE 1931 chromaticity of Ca doped Ba2Al2Si10N1404：Eu2＋ phosphors could be adjusted over a wide range concentration of Ca2＋ and Eu2＋.