Site selective and enhanced luminescence of SrGe4O9:Mn4+ red phosphor via Ti4+ or Sn4+ codoped

Sn4+/Ti4+ co-doped SrGe4O9:Mn4+ deep red phosphors were synthesized via high temperature solid state method. The structure, morphology and photoluminescence properties were investigated by XRD, SEM and fluorescent spectrometer. The obtained samples exhibit strong deep red emission located at 660 nm under 430 nm excitation. The optimum concentration of Mn4+ was about 1.2 mol% and concentration quenching mechanism was related to d-d interaction. Co-doping of Ti4+ (Sn4+) enhanced emission intensity of SrGe4O9 by 22% (13%) due to the changed coordination environment of Mn4+ and efficient energy transfer between Ti4+ (Sn4+) and Mn4+. Sn4+ may be substituted the Ge1 site and Ti4+ replaced the Ge2 site. The fabricated LED showed a white light with chromaticity coordinates (0.3429, 0.2941). The results indicated that site selective occurred and SrGe4O9:Mn4+, Ti4+ (Sn4+) have potential to supplementary red light and package white LEDs.

Automated summary

Sn4+/Ti4+ co-doped SrGe4O9:Mn4+ deep red phosphors were synthesized and showed strong emission intensity at 660 nm under 430 nm excitation. The optimal concentration of Mn4+ was found to be 1.2 mol%, and co-doping with Ti4+ (Sn4+) improved emission intensity by changing the coordination environment of Mn4+ and facilitating energy transfer. The fabricated LED exhibited white light with promising potential for supplemental red light and white LED packaging.