1 Key Laboratory of Catalysis and Material Science of the State Ethnic Affairs Commission & Ministry of Education, Hubei Province, College of Chemistry and Material Science, South Central University for Nationalities, Wuhan, 430074, PR China
In our study, the 1% mol Eu2+ doped Li2CaSiO4: B3+ phosphors were prepared by the combustion method as fluorescent material for ultraviolet, light-emitting diodes (UV-LEDs) used as a light source. The properties of Li2 (Ca0.99, Eu0.01) SiO4: B3+ phosphors with urea concentration, doping boric acid and a series of initiating combustion temperature were investigated. The crystallization and particle sizes of Li2 (Ca0.99, Eu0.01) SiO4: B3+ has been investigated by using powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). Luminescence measurements showed that the phosphors can be efficiently excited by UV to the visible region, and exhibited bluish green light with a peak of 480 nm. The results showed that the boric acid was effective in improving the luminescence intensity of Li2 (Ca0.99, Eu0.01) SiO4: B3+ and the optimum molar ratio of boric acid to calcium nitrate was about 0.06. The optimized phosphors Li2 (Ca0.99, Eu0.01) SiO4: B0.063+ showed 180% improved emission intensity compared with that of the Li2 (Ca0.99, Eu0.01) SiO4 phosphors under ultraviolet (λex =287 nm) excitation.
If the inline PDF is not rendering correctly, you can download the PDF file here.
 S. Nakamura, S. Pearton and G. Fasol: The Blue Laser Diode, 2nd ed., Springer-Verlag, Berlin 2000.
 N. Narendran, N. Maliyagoda, A. Bierman, R. Pysar and M. Overington: “Characterizing white LEDs for general illumination applications”, Proc SPIE Int Soc Opt Eng, Vol. 3938, (2000), p. 240.
 M.G. Craford: “Visible LEDs: the trend toward high-powder emitters and remaining challenges for filid state lighting”, Proc SPIE Solid State Lighting II, Vol. 4776, (2002), pp. 1–8.
 J.K. Sheu, C.H. Kuo, S.J. Chang, Y.K. Su, L.W. Wu, Y.C. Lin, J.M. Tsai, R.K. Wu and G.C. Chi: “White-Light emission from near UV InGaN-GaN LED Chip precoated with blue/green/red/ phosphors”, IEEE. Photonic. Technol. Lett, Vol. 15, (2003), p. 18. http://dx.doi.org/10.1109/LPT.2002.805852
 E.F. Schubert and J.K. Kim: “Solid-State Light Sources Getting Smart”, Science, Vol. 308, (2005), pp. 1274–1278. http://dx.doi.org/10.1126/science.1108712
 J.K. Park, M.A. Lim, C.H. Kim, H.D. Park, J.T. Park and S.Y. Choi: “White light-emitting diodes of GaN-based Sr2SiO4: Eu and the luminescent properties”, Appl. Phys. Lett, Vol. 82, (2003), pp. 683–685. http://dx.doi.org/10.1063/1.1544055
 J.K. Park, C.H. Kim, S.H. Park, H.D. Park and S.Y. Choi: “Application of strontium silicate yellow phosphor for white light-emitting diodes”, Appl. Phys. Lett, Vol. 84, (2004), p. 1648.
 J.S. Kim, J.K. Kang, P.E. Jeon, J.C. Chol, H.L. Park and T.W. Kim: “GaN-based white-light-emitting diodes fabricated with a mixture of Ba3MgSi2O8: Eu2+ and Sr2SiO4: Eu2+ phosphors”, Jpn. J. Appl. Phys., Vol. 43, (2004), pp. 989–992. http://dx.doi.org/10.1143/JJAP.43.989
 J.S. Kim, P.E. Jeon, Y.H. Park, J.C. Choi and H.L. Park: “White-light generation through ultraviolet-emitting diode and white-emitting phosphor”, Appl. Phys. Lett, Vol. 85, (2004), p. 3696. http://dx.doi.org/10.1063/1.1808501
 M. Pardha Saradhi and U.V. Varadaraju: “Photluminescence studies on Eu2+-activated Li2SrSiO4-a potential orange-yellow phosphor for solid-state lighting”, Chem. Mater, Vol. 18, (2006), pp. 5267–5272. http://dx.doi.org/10.1021/cm061362u
 Y. Narukawa, I. Niki, K. Izuno, M. Yamada and Y. Mukai: “Phosphor-Conversion White Light Emitting Diode Using InGaN Near-Ultraviolet Chip”, Jpn. J. Appl. Phys., Vol. 41, (2002), pp. 371–373. http://dx.doi.org/10.1143/JJAP.41.L371
 A.M. Srivastava, H.A. Comanzo and H.A. Comanzo: “Phosphors for down converting ultraviolet light of LEDs to blue-green light”, U.S. Patent. No. 6, 466, 135, (2002), pp. 12.
 J. Liu, J.Y. Sun and C.S. Shi: “A new luminescent material: Li2CaSiO4: Eu2+”, Mater. Lett, Vol. 60, (2006), pp. 2830–2833. http://dx.doi.org/10.1016/j.matlet.2006.01.100
 Z.C. Wu, J.X. Shi, J. Wang, M.L. Gong and Q. Su: “A novel blue-emitting phosphor LiSrPO4: Eu2+”, J. Solid State Chem., Vol. 179, (2006) pp. 2356–2360. http://dx.doi.org/10.1016/j.jssc.2006.04.030
 M. Veith, S. Mthur, A. Kareiva, M. Jilavi, M. Zimmer and V. Huch: “Low temperature synthesis of nanocrystalline Y3Al5O12 (YAG) and Ce-doped Y3Al5O12 via different sol-gel methods”, J. Mater. Chem., Vol. 9, (1999) pp. 3069–3079. http://dx.doi.org/10.1039/a903664d
 T.M. Chen, S.C. Chen and C.J. Yu: “Garnet phosphor nanoparticles derived from oxalate coprecipitation”, J. Solid State Chem., Vol. 144, (1999), pp. 437–441. http://dx.doi.org/10.1006/jssc.1999.8202
 K.Y. Jung, H.W. Lee and H.K. Jung: “Luminescent properties of (Sr, Zn)Al2O4: Eu2+, B3+ particles as a potential green phosphor for UV LEDs”, Chem. Mater, Vol. 18, (2006), pp. 2249–2255. http://dx.doi.org/10.1021/cm060003w
 Y. Xinbin, Z. Chunlei, H. Xionghong, P. Zifei and Y. Shiping: “The influence of some processing conditions on luminescence of SrAl2O4: Eu2+ nanoparticles produced by combustion method”, Mater. Lett, Vol. 58, (2004), pp. 1087–1091. http://dx.doi.org/10.1016/j.matlet.2003.08.022
 J.A. Gard and A.R. West: “Preparation and crystal structure of Li2CaSiO4 and isostructural Li2CaGeO4”, J. Solid State Chem., Vol. 7, (1973), p. 422. http://dx.doi.org/10.1016/0022-4596(73)90171-0
 J.J. Kingsley, K.C. Patil: “A Novel Combustion Process for the Synthesis of Fine Particle alpha-Alumina and Related Oxide Materials”, Mater. Lett, Vol. 6, (1988), pp. 427–432. http://dx.doi.org/10.1016/0167-577X(88)90045-6
 H.E. Bergan and L.B. Hockessin: “Ceramic dielectric compositions and method for improving sinterability”, United States: 5, 011, 804, Apr. 30, 1991.
 J.M. Sun, T. Dekorsy, W. Skorupa, A. Mücklich, B. Schmidt and M. Helm: “Efficient silicon light emitting diodes by boron implantation: the mechanism”, Opt. Mater, Vol. 27, (2005), pp. 1041–1045. http://dx.doi.org/10.1016/j.optmat.2004.08.059
 W. Jia, D. Jia, T. Rodriguez, D.R. Evans, R.S. Meltzer and W.M. Yen: “UV excitation and trapping centers in CaTiO3: Pr3+”, J. Lumin., Vol. 119/120, (2006), pp. 13–18. http://dx.doi.org/10.1016/j.jlumin.2005.12.067
 A. Nag and T.R.N. Kutty: “Role of B2O3 on the phase stability and long phosphorescence of SrAl2O4: Eu, Dy”, J. Alloys Compd., Vol. 354, (2003), pp. 221–231. http://dx.doi.org/10.1016/S0925-8388(03)00009-4
 J.S. Duk, P.J. Kyu and L.S. Hyuk: “Photoluminescence properties of Eu2+ activated Sr3SiO5”, J. Mater. Sci., Vol. 41, (2006), pp. 3139–3141. http://dx.doi.org/10.1007/s10853-006-6436-8
 P. Dorenbos: “Energy of the first 4f
7 → 4f
6 5d transition of Eu2+ in inorganic compounds”, J. Lumin., Vol. 104, (2003). pp. 239–260. http://dx.doi.org/10.1016/S0022-2313(03)00078-4