Enhanced luminescence intensity and color purity of the red emitting LnVO4:Eu3+@ SiO2 (Ln=Gd, Y and Gd/Y) powder phosphors

• Published in: Materials research bulletin 2013-02, Vol.48 (2), p.512-520
• Main Authors: Rambabu, U., Han, Sang-Do
• Format: Article
• Language: English
• Subjects: A. Optical materials; B. Chemical synthesis; D. Luminescence
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2012.11.004

[Display omitted] ► Tetragonal phase lanthanide vanadates doped with Eu3+ were synthesized. ► Luminescence enhancement was done by optimizing the host (Gd,Y) and SiO2 coatings. ► SiO2 coating was characterized by SEM-EDAX, FT-IR and PL techniques. ► 5D0→7F2 domination over 5D0→7F1 indicates the absence of an inversion symmetry. ► Y0.95VO4:Eu3+@ SiO2(10vol.%) is found to be a novel enhanced red emitting phosphor. An attempt was made to enhance the luminescence properties of LnVO4:Eu3+@ SiO2 (Ln=Gd, Y and Gd/Y) powder phosphors. Pure phase with tetragonal structure of the produced phosphors was confirmed by XRD profiles. Sub-micron sized phosphors have shown 35% more PL intensity than the bulk, which was further improved 20.22% with SiO2 shell coating. SiO2 shell coating was optimized by SEM-EDAX, FT-IR, PL and TEM measurements. Emission intensities of the transition, 5D0→7F2 have dominated 5D0→7F1, which indicated the lowering of an inverse symmetry in the vicinity of Eu3+ ions. Luminescence intensity and color purity were enhanced with the host modification by substituting Gd3+ with Y3+ sites, followed by SiO2 coating. Based on the systematic investigations carried out, the phosphor Y0.95VO4:Eu3+0.05@ SiO2 is suggested to be a novel contender for its suitable red emission in certain displays or lighting.