Red emitting MTiO3 (M = Ca or Sr) phosphors doped with Eu3+ or Pr3+ with some cations as co-dopants

• Ca(or Sr)TiO3:Eu3+,N+ (N = Li, Na or K) powders were prepared by combustion method.
• CaTiO3:Pr3+, N+ (N = Li, Na, Ag, K, Gd or La) were synthesized by combustion method.
• PL intensity of CaTiO3:Pr3+ increases when co-doping with Li, Na, Ag, K, Gd or La.
• Li+co-doping results in an increase of PL intensity in Ca(or Sr)TiO3:Eu3+ powders.

Ca (or Sr)TiO3:Eu3+, M (Li+ or Na+ or K+) and CaTiO3:Pr3+, M (Li+ or Na+ or Ag+ or K+ or Gd3+ or La3+) powders were prepared by combustion synthesis method and the samples were further heated to ∼1000 °C to improve the crystallinity. The structure and morphology of materials were examined by X-ray diffraction (XRD) and a scanning electron microscopy (SEM). The morphologies of SrTiO3:Eu3+, CaTiO3:Eu3+ or CaTiO3:Pr3+ powders co-doped with other metal ions were very similar. Small and coagulated particles of nearly cubical shapes with small size distribution having smooth and regular surface were formed. Photo-luminescence spectra of CaTiO3:Pr3+ and co-doped either with Li+, Na+, K+, Ag+, La3+ or Gd3+ ions showed red emissions at 613 nm due to the 1D2 → 3H4 transition of Pr3+. The variation of intensity of emission peak with different co-doping follows the order: K+ > Ag+ > Na+ > Li+ > La3+ > Gd3+. The characteristic emissions of CaTiO3:Eu3+ lattices had strong emission at 614 and 620 nm for 5D0 → 7F2 with other weak transitions observed at 580, 592, 654, 705 nm for 5D0 → 7Fn transitions where n = 0, 1, 3, 4 respectively in all host lattices. Photoluminescence intensity in SrTiO3:Eu3+ is more than CaTiO3:Eu3+ lattices. A remarkable increase of photoluminescence intensity (in 5D0 → 7F2 transition) was observed if co-doped with Li+ ions in CaTiO3:Eu3+ and SrTiO3:Eu3+.