Luminescence Property of Eu~(2+) Doped Strontium Silicate Yellow Phosphor for White Light Emitting Diode

摘要

Eu~(2+) activated strontium silicate (Sr_3SiO_5:Eu~(2+)) yellow phosphor was prepared by the conventional solid-state reaction technique in reduction atmosphere with starting materials SrCO_3, SiO_2 and EU_2O_3. The phase, morphology and luminescence property of the samples were analyzed. The X-ray diffraction analysis showed the main phase in all samples is tetragonal Sr_3SiO_5. With Eu~(2+) ions doped into the host lattice, the Sr_3SiO_5:Eu~(2+) phosphors absorb light energy in the UV-visible spectrum region and show an intense broad emission band in the yellow colour range (around 570 nm) and a weak band in the blue region (around 470 nm). The excitation and the emission bands are originated from the 4f-5d transition of Eu~(2+) ions. When the concentration of Eu~(2+) ions increases, the emission peaks of phosphors shift to longer wavelengths. The effective emission in the yellow colour indicates that phosphor as potential candidates for white light-emitting-diodes.