A novel red long-lasting phosphor, (Y1-xGdx)2O3:Eu3+, Sm3+, Si4+, Mg2+, was synthesized by the co-precipitation method using oxalate precipitation as the precursor. X-ray diffraction (XRD), scanning electronic microscopy (SEM), integrated thermal analyzer (TG), and photoluminescence spectra (PL) as well as the ST-900PM weak light photometer were used to study the synthesis conditions, morphology, luminescence properties, and the decay time of the phosphor. The XRD results show that the products synthesized at 1400℃ for 4 h have good crystallization without any detectable impurity phases. Based on the PL spectra, the optimal conditions are as the following. The molar ratios of Y3+ to Gd3+ and Eu3+ to Sm3+ are 2:8 and 3:1, respectively, and the contents of Mg2+ and SiO2 are 5mol% and 3mol%, respectively. The decay time monitored by the ST-900PM weak light photometer is 7200 s, increasing 44% and 100%, respectively, compared with the Eu3+ and Sm3+ single-doped phosphors. The results indicate that the energy transfer is from Sm3+ to Eu3+ ion, and Sm3+ is a good sensitizer to Eu3+.
A novel red long-lasting phosphor, (Y1-xGdx)2O3:Eu3+, Sm3+, Si4+, Mg2+, was synthesized by the co-precipitation method using oxalate precipitation as the precursor. X-ray diffraction (XRD), scanning electronic microscopy (SEM), integrated thermal analyzer (TG), and photoluminescence spectra (PL) as well as the ST-900PM weak light photometer were used to study the synthesis conditions, morphology, luminescence properties, and the decay time of the phosphor. The XRD results show that the products synthesized at 1400℃ for 4 h have good crystallization without any detectable impurity phases. Based on the PL spectra, the optimal conditions are as the following. The molar ratios of Y3+ to Gd3+ and Eu3+ to Sm3+ are 2:8 and 3:1, respectively, and the contents of Mg2+ and SiO2 are 5mol% and 3mol%, respectively. The decay time monitored by the ST-900PM weak light photometer is 7200 s, increasing 44% and 100%, respectively, compared with the Eu3+ and Sm3+ single-doped phosphors. The results indicate that the energy transfer is from Sm3+ to Eu3+ ion, and Sm3+ is a good sensitizer to Eu3+.