Paper AS-ThP19
Generation of White Light from Sr₂SiO₄ Doped with Lanthanides

Thursday, October 31, 2013, 6:00 pm, Room Hall B

In recent years, the study of the synthesis and characterization of white light emitting phosphors for use in white light emitting diodes (LEDs) has generated attention worldwide. In white light LEDs, white light can be generated by combination of light of three primary colors (red, green and blue) emitted from different LED chips¹ or combination of blue LED with yellow-emitting phosphor materials^2,3. The problems with these traditional white LEDs is that the yellow YAG:Ce³⁺ phosphor has been reported to show high thermal quenching and poor colour rendition, and that the efficiency of the blue emission is often affected by re-absorption by the red or green phosphor in the three converter system. It is important to find a phosphor that can be excited under near-ultra-violet and the blue region³. In recent studies it has been established that white light can be generated by doping one or more activator(s) in one matrix. For example, in this study white photoluminescence was generated when Sr₂SiO₄ single doped with Dy³⁺ or co-doped with Tb³⁺ and Eu³⁺ was excited using a monochromatized xenon lamp. The structure, particle morphology, chemical composition and oxidation states, photoluminescence (PL) and decay properties of the phosphor were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy and PL spectroscopy, respectively. The XRD patterns showed that a monoclinic phase of Sr₂SiO₄ was crystallized. The decay characteristic data showed that the phosphor consist of single exponential decay curves. The X-ray diffraction data confirmed that.

References

(1) Yanmin, Q.; Xinbo, Z.; Xiao, Y.; Yan, C.; Hai, G.; Journal Rare Earths2009, 27(2), 323

(2) J.K. Park, M.A. Lim, C.H. Kim, H.D. Park Applied Physics Letters2003, 82(5), 683

(3) Yao, S.; Chen, D.; Central European Journal of Physics2007, 5(4), 558