Abstract:

In order to obtain a single matrix white phosphor，g-C₃N₄ blue phosphor was prepared through thermal decomposition method using the melamine as raw material，and Sr_0.92MoO₄：0.08Eu³⁺（SMO：E） and Sr_0.82MoO₄：0.08Eu³⁺，0.10K⁺ （SMO：EK） red phosphors were prepared through high temperature solid state method，and the composite phosphors Sr_0.82MoO₄：0.08Eu³⁺，0.10K⁺@0.013g-C₃N₄（SMO：EK-CN） were prepared by precipitation adsorption reaction.The phosphors were characterized by the powder X-ray diffraction（XRD），infrared spectroscopy（IR），fluorescence spectoscopy and thermal quenching analysis.The effects of single-doping Eu³⁺，co-doping Eu³⁺，K⁺，and co-doping Eu³⁺，K⁺，g-C₃N₄ on the luminescence properties of the phosphors were investigated.The results showed that the synthesized phosphors were all tetragonal.The change of cell volume after doping proved that Eu³⁺，K⁺，g-C₃N₄ had entered the lattice of SrMoO₄.IR spectra of SMO：EK-CN showed the characteristic absorption peaks of the molybdate and g-C₃N₄，indicating that g-C₃N₄ had been successfully doped in SMO：EK phosphor.Under the excitation of UV at 393 nm，8%（mass fraction） of Eu³⁺-doped，the luminescence intensity of SMO：E red phosphor reached the maximum；When the mass fraction of Eu³⁺ and K⁺ were 8% and 10%，respectively，the luminescence intensity of SMO：EK red phosphor was the strongest.Changing the mass fraction of g-C₃N₄，the composite phosphors could be transformed from red light to blue light.When the mass fraction of g-C₃N₄ was 1.3%，the chromaticity coordinate of SMO：EK-CN was（0.31，0.21），which was close to the chromaticity coordinate of standard white light （0.33，0.33）.The activation energy of the phosphor in the thermal quenching process was 0.93 eV，indicating that it had good thermal stability and potential application prospect in white LED.

Key words: white light, phosphor, luminescence property, SrMoO₄, g-C₃N₄