Significant enhancement of luminescence intensity of CaTiO3:Eu3+ red phosphor prepared by sol–gel method and co-doped with Bi3+ and Mg2+

In this study, red phosphors Ca1−nMgnTiO3:Eu3+,Bi3+ were prepared by the sol–gel method and the impact of single dopant, co-dopants and solid solutions on the photoluminescence of the samples has been also investigated. Our results show that the crystal structure of the host does not have distinct changes when doped with Eu3+, Bi3+ and/or Mg2+. The emission intensity at 615 nm of Eu3+ increased at the presence of Bi3+ ions owing to the energy transfer from Bi3+ ion to Eu3+ ion. Moreover, with the addition of Mg2+, the red emission of the phosphor was further enhanced due to the stronger absorption at 399 and 467 nm, which match well with the emission of near-UV (395–400 nm) and blue-LED (450–470 nm), respectively. Under the near-UV (399 nm) or blue light (467 nm) excitation, the fluorescence quantum yield of the optimal composition Ca0.9Mg0.1TiO3:0.18Eu3+,0.018Bi3+ is 0.36 and 0.41, respectively, which possesses the higher photoluminescence intensity than CaMoO4:0.2Bi3+,0.05Eu3+ and the commercially available Y2O2S:Eu3+ phosphors under near-UV excitation. Based on these results, we are currently considering the potential application of Ca0.9Mg0.1TiO3:Eu3+,Bi3+ as a near-UV or blue-chip convertible red-emitting phosphor.