Luminescent properties of SrSi2O2N2:Eu2+ by the two-step synthesis

• Published in: Journal of alloys and compounds 2015-11, Vol.650, p.470-474
• Main Authors: Li, Xucheng, Zhang, Rongfen, Cui, Ruirui, Deng, Chaoyong
• Format: Article
• Language: English
• Subjects: Defects; Luminescence; Phosphor; Precursor; SrSi2O2N2:Eu2
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2015.07.266

SrSi2O2N2:Eu2+ phosphors were synthesized by a high temperature solid-state reaction method using Sr2SiO4 as the precursor. The effect of different Eu valence and partial substitution of Sr2+ by Ba2+ in Sr2SiO4 on the luminescence properties of SrSi2O2N2:Eu2+ was studied. Phase characteristics and luminescence properties of the samples were investigated in detail by mean of X-ray diffraction and fluorescence spectrophotometer analysis. The results revealed that there exist charge defects originated from the replacement of Sr2+ by Eu3+ in Sr2SiO4:Eu3+ and anion vacancies which likely occur in Sr1.95Ba0.05SiO4:Eu2+ due to partial substitutions of Sr2+ by Ba2+. The defects in the Sr2SiO4 play a role in luminescence properties of SrSi2O2N2:Eu2+. The emission intensity of the samples that use Sr2SiO4:Eu3+ and Sr1.95Ba0.05SiO4:Eu2+ as precursor was increased by 17% and 11% respectively when compared with that of using Sr2SiO4:Eu2+ as precursor(0.5 mol% Eu2+ concentration). And with the increasing Eu2+ concentration, the increasing degree of luminescence intensity of the samples declines rapidly. In additional, at 200 °C, 75–78% emission intensity of the phosphors measured at room temperature were maintained. Furthermore, partial replacement of Sr2+ by Ba2+ in samples can reduce thermal quenching. [Display omitted] •The effect of Eu valence and substitution of Sr2+ by Ba2+ in Sr2SiO4 was studied.•The defects in Sr2SiO4 play a role on the PL property of SrSi2O2N2:Eu2+.•With the increasing of Eu2+, concentration quenching plays main part in PL property.