Novel yellowish-green emitting luminescence in Ca7Si2P2O16:Eu2+ phosphor

•Green-origin-emitting phosphors of Eu2+-doped Ca7Si2P2O16 were firstly prepared by chemical sol–gel method.•The tunable luminescence color was realized by the changing Eu2+-doping in Ca7Si2P2O16.•Ca7Si2P2O16:Eu2+ displays two typical luminescence centers with the emission depending on Eu2+ doping.•Eu2+-doped Ca7Si2P2O16 phosphor has an excellent thermal stability on the temperature quenching.

Color tunable green-origin-emitting phosphor of Eu2+-doped phosphate-silicate Ca7Si2P2O16 was prepared by chemical sol–gel method. The X-ray powder diffraction, the photoluminescence excitation and emission spectra, time resolved spectra, and thermal stability were measured. The excitation spectra can well match with the emission light of near UV-LED chips (360–400 nm). The tunable luminescence was realized by changing Eu2+-doping concentration. Ca7Si2P2O16:Eu2+ displays two typical luminescence centers, which were suggested to originate from two Ca2+ sites in the host. With increasing Eu2+ doping concentrations, the green emission band shifts to long wavelength. Energy transfer between the two different Eu2+ ions is discussed by analyzing the photoluminescence excitation and emission spectra, concentration-dependent luminescence intensity, and lifetimes. The dependence of the luminescence intensity of Ca7Si2P2O16:Eu2+ on temperatures was measured. The activation energy (ΔE) for thermal quenching was reported.

Graphical abstractThe phosphor has two separated emission centers with the dependent emission intensity on Eu2+ doping. There is a red-shift in the emission due to energy transfer with increasing the Eu2+-doping.Figure optionsDownload full-size imageDownload as PowerPoint slide