A novel red emitting phosphor of Eu3+ doped Sr2La2MgW2O12 for white light emitting diodes

• Sr2La2MgW2O12:Eu3+ phosphor has been synthesized.
• Its structure and luminescent properties were well studied and characterized.
• It exhibits red (613 nm) emission peaks.
• The results indicate that Sr2La2MgW2O12:Eu3+ could be a potential red phosphor for WLEDs.

In this paper, we reported a series of Eu3+ activated Sr2La2MgW2O12 phosphors synthesized by the solid state reaction method. X-ray diffraction analysis revealed that Sr2La2MgW2O12 doped with Eu3+ was pure phase. Upon the 464 nm light excitation, Sr2La2MgW2O12:Eu3+ phosphors exhibited a red emission centered at 613 nm, originated from the 5D0–7F2 transition of Eu3+ ions. The optimum concentration of Eu3+ for the highest luminescence was found to be 20 mol%, and the critical distance was calculated to be 11.98 Å. The Commission International de l’Eclairage (CIE) chromaticity coordinate of Sr2La1.8MgW2O12:0.20Eu3+ was (x = 0.626, y = 0.374), which was closed to the standard of NTSC (x = 0.670, y = 0.330). The results indicated that Sr2La2MgW2O12:Eu3+ could be a potential red phosphor for white light-emitting diodes (WLEDs).

It can be seen that the excitation spectra consist of 2 parts: one is an intense, broad band from 250 nm to 350 nm, and another is sharp lines from 350 nm to 500 nm. The broad band blow 350 nm is attributed to the change transfer (CT) transition between metal cations and oxygen anions. The spectrum above 350 nm shows several sharp peaks, and all of them are attributed to the Eu3+ ions’ characteristic 4f–4f transitions 362 nm (7F0–5D4), 382 nm (7F0–5G4,5L7), 393 nm (7F0–5L6), 415 nm (7F0–5D3), 464 nm (7F0–5D2) and 533 nm (7F0–5D1), respectively.Figure optionsDownload as PowerPoint slide