Europium-activated barium/strontium silicates for near-UV light emitting diode applications

This paper reports on the luminescence properties of submicron-sized green-yellow emitting (Ba1−xSrxEu0.03)2SiO4 (0≤x≤1) phosphors. These phosphors were prepared by a modified sol–gel/Pechini method. The X-ray diffraction analysis shows that the single phase products are obtained. The particle size - ranges from 200 to 500 nm with a spherical or needlelike shape depending on x. These phosphors show strong absorption in the near UV range and the photoluminescence emission spectra consist of a strong broad green-yellow band centered between 512 and 570 nm, depending on x. Furthermore, the phosphors have high quantum efficiencies: 94% for x=0 and 85% for x=0.25. The emission lifetime at 400 K is 97% of that at 40 K, demonstrating good thermal stability.