Photoluminescence properties and charge compensation investigations of novel orange-emitting Eu3+ doped Na4Ca4(Si6O18) phosphors

• DOI: 10.1007/s10854-016-4615-1
• Publication Date: 2016-03-08T03:24:44Z
• Authors: Nenghuo Wang; Weiren Zhao; Junhua Chen; Jianqing Wang; Yingjun Meng; Shuangping Yi; Yanjuan Zhu
• Keywords: Chromaticity; Thermal Stability

A series of polycrystalline Na4Ca4(Si6O18):Eu3+ orange emitting phosphors were synthesized by a conventional high-temperature solid-state reaction. The phase formation was confirmed by X-ray power diffraction analysis. The excitation spectra show a strong host absorption indicating an efficient energy transfer process from O2− to Eu3+ ions. Upon NUV radiation, the phosphors showed strong red emission around 610 nm (5D0 → 7F2) and orange emission around 591 nm (5D0 → 7F1), but the 5D1,2,3 emission nearly can not be seen. Compared with the luminescence properties of Li+, Na+, and K+ co-doped samples, we deduced that Na+ ions probably prefer to dope into the intrinsic Na vacancies rather than Ca2+ ions vacancies in Na4Ca4(Si6O18) crystal. Thermal stability properties, quantum efficiency and chromaticity coordinates of the phosphors have been investigated for the potential application in white LEDs.