Persistent luminescence in MSi2O2N2:Eu phosphors

In this work we study the persistent luminescence properties of europium-doped alkaline earth silicon oxynitrides (CaSi2O2N2, SrSi2O2N2 and BaSi2O2N2). All compounds show afterglow emission, with an emission spectrum which is similar to the steady state photoluminescence. The afterglow decay time for BaSi2O2N2:Eu and SrSi2O2N2:Eu is about 50 and 100 minutes respectively, while for CaSi2O2N2:Eu the afterglow intensity is very low. Although the persistent luminescence can be induced by ultraviolet light (250-300 nm) in all three phosphors, only for BaSi2O2N2:Eu low energy radiation (350-500 nm) allows filling of the traps responsible for the afterglow. ©2012 Optical Society of America OCIS codes: (160.2900) Optical storage materials; (160.5690) Rare-earth-doped materials; (170.6280) Spectroscopy, fluorescence and luminescence; (160.2540) Fluorescent and luminescent materials; (250.5230) Photoluminescence. References and links 1. K. Van den Eeckhout, P. F. Smet, and D. Poelman, “Persistent luminescence in Eu-doped compounds: a review,” Materials 3(4), 2536–2566 (2010). 2. T. Matsuzawa, Y. Aoki, N. Takeuchi, and Y. Murayama, “New long phosphorescent phosphor with high brightness, SrAl2O4:Eu ,Dy,” J. Electrochem. Soc. 143(8), 2670–2673 (1996). 3. R. Mueller-Mach, G. Mueller, M. R. Krames, H. A. Höppe, F. Stadler, W. Schnick, T. Juestel, and P. Schmidt, “Highly efficient all-nitride phosphor-converted white light emitting diode,” Phys. Status Solidi A 202(9), 1727– 1732 (2005). 4. R. J. Xie, N. Hirosaki, K. Sakuma, and N. Kimura, “White light-emitting diodes (LEDs) using (oxy) nitride phosphors,” J. Phys. D Appl. Phys. 41(14), 144013 (2008). 5. P. F. Smet, A. B. Parmentier, and D. Poelman, “Selecting conversion phosphors for white light-emitting diodes,” J. Electrochem. Soc. 158(6), R37–R54 (2011). 6. V. Bachmann, C. Ronda, O. Oeckler, W. Schnick, and A. Meijerink, “Color point tuning for (Sr,Ca,Ba)Si2O2N2:Eu 2+ for white light LEDs,” Chem. Mater. 21(2), 316–325 (2009). 7. V. Bachmann, T. Justel, A. Meijerink, C. Ronda, and P. J. Schmidt, “Luminescence properties of SrSi2O2N2 doped with divalent rare earth ions,” J. Lumin. 121(2), 441–449 (2006). 8. M. Y. Wang, X. Zhang, Z. D. Hao, X. G. Ren, Y. S. Luo, H. F. Zhao, X. J. Wang, and J. H. Zhang, “Long-lasting phosphorescence in BaSi2O2N2:Eu 2+ and Ba2SiO4:Eu 2+ phases for x-ray and cathode ray tubes,” J. Electrochem. Soc. 157(2), H178–H181 (2010). 9. A. J. J. Bos, R. M. van Duijvenvoorde, E. van der Kolk, W. Drozdowski, and P. Dorenbos, “Thermoluminescence excitation spectroscopy: A versatile technique to study persistent luminescence phosphors,” J. Lumin. 131(7), 1465–1471 (2011). 10. P. F. Smet, K. Van den Eeckhout, A. J. J. Bos, E. van der Kolk, and P. Dorenbos, “Temperature and wavelength dependent trap filling in M2Si5N8:Eu (M = Ca, Sr, Ba) persistent phosphors,” J. Lumin. 132(3), 682–689 (2012). 11. J. A. Kechele, O. Oeckler, F. Stadler, and W. Schnick, “Structure elucidation of BaSi2O2N2 A host lattice for rare-earth doped luminescent materials in phosphor-converted (pc)-LEDs,” Solid State Sci. 11(2), 537–543 (2009). 12. O. Oeckler, F. Stadler, T. Rosenthal, and W. Schnick, “Real structure of SrSi2O2N2,” Solid State Sci. 9(2), 205– 212 (2007). 13. H. A. Höppe, F. Stadler, O. Oeckler, and W. Schnick, “Ca[Si2O2N2] A novel layer silicate,” Angew. Chem. Int. Ed. 43(41), 5540–5542 (2004). #160143 $15.00 USD Received 20 Dec 2011; revised 23 Feb 2012; accepted 23 Feb 2012; published 27 Feb 2012 (C) 2012 OSA 1 March 2012 / Vol. 2, No. 3 / OPTICAL MATERIALS EXPRESS 341 14. F. Stadler, R. Kraut, O. Oeckler, S. Schmid, and W. Schnick, “Synthesis, crystal structure and solid-state NMR spectroscopic investigation of the oxonitridosilicate BaSi6N8O,” ChemInform 36(43), 1773–1778 (2005). 15. F. Stadler and W. Schnick, “The new layer-silicates Ba3Si6O9N4 and Eu3Si6O9N4,” Z. Anorg. Allg. Chem. 632(6), 949–954 (2006). 16. D. Poelman, N. Avci, and P. F. Smet, “Measured luminance and visual appearance of multi-color persistent phosphors,” Opt. Express 17(1), 358–364 (2009). 17. K. Van den Eeckhout, P. F. Smet, and D. Poelman, “Luminescent afterglow behavior in the M2Si5N8: Eu family (M = Ca, Sr, Ba),” Materials 4(6), 980–990 (2011). 18. K. Korthout, K. Van den Eeckhout, J. Botterman, S. Nikitenko, D. Poelman, and P. F. Smet, “Luminescence and x-ray absorption measurements of persistent SrAl2O4:Eu,Dy powders: Evidence for valence state changes,” Phys. Rev. B 84(8), 085140 (2011).