Enhanced red photoluminescence in chain-like SrAl2O4:Eu3+ nanophosphors: utilizing charge compensation by modulating Na+ co-doping concentration

In the recent days, rare-earth doped phosphors have attracted an immense attraction in luminescence field for various solid-state lighting and electronic display device applications. However, need of efficient red phosphor is a prevalent challenge in this field. Herein, we report a bright red light emitting Na + co-doped SrAl 2 O 4 :Eu 3+ phosphor which is synthesized by modified sol–gel technique. These nanophosphors show excellent red emission due to characteristic 5 D 0 → 7 F j ( j = 1, 2, 3, 4) transitions of the doped Eu 3+ ions excited by 394 nm. Photoluminescence studies of both Eu 3+ doped SrAl 2 O 4 and Na + co-doped SrAl 2 O 4 :Eu 3+ has shown more than fourfold increase in the intensity for optimum Na + addition. The improved decay time obtained from decay measurement has revealed that the co-doped Na + has successfully reduced the nonradiative transitions. Thus, addition of monovalent Na + to Eu 3+ doped SrAl 2 O 4 was found to be effective to address the charge imbalance problem along with significant enhancement in luminescence intensity and decay time. The results suggest that this nanophosphor could be a major candidate in the rapidly increasing field of solid-state lighting applications.