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1 Journal of the Korean Ceramic Society Vol. 47, No. 6, pp. 503~508, DOI: /KCERS The High Density Sintering of Green-emitting -SiAlON:Eu Ceramic Plate Phosphor Young-Jo Park, Sung-Hoon Lee, Wook-Kyung Jang, Chang-Bun Yoon*, and Chulsoo Yoon* Engineering Ceramics Research Group, Korea Institute of Materials Science, Changwon, , Korea *Electro Materials and Device Center, Samsung LED, Suwon , Korea (Received September 27, 2010; Revised October 18, 2010; Accepted October 26, 2010) Ÿ -SiAlON:Eu v p xÿ e y Á zá Á *Á * w» (KIMS) * z ( ; ; ) ABSTRACT Eu 2+ -doped β-sialons (Si 6-z :Eu y ) are recognized as promising phosphor materials to build an white LED for lighting application due to its excellent absorption/emission efficiency in the long wave length region. In this research, the fabrication of β- SiAlON:Eu plate phosphor by sintering was investigated with fixed Eu content(y) and varied composition of the host lattice(z). The addition of the activator Eu 2 lead to enhanced densification by forming the transient liquid phase. The refinement of a composition by the calculated lattice parameter indicated that the measured composition of the fabricated specimens is nearly same to that of designed one. The single phase β-sialon:eu plate with relative density of 96.4% was achieved by addition of 2 wt% CaO, which implies the possibility of full densification by adjusting the processing variables. Key words : Phorphor, LED, SiAlON, Sintering, Plate 1. LED ƒ t LEDe+xŸ, xk xÿ yw w r p LEDe s.» r p 1) ³ yw, û, y Ÿn w Ÿp y qj, w qj ƒ y w š. w v p xk xÿ yw w» w w w» p w qj y š LED w» š. ù x ¾ v p xÿ v mk t œ š v p xÿ w w š w. v p xÿ w qj x 2) w» w v Ÿn (translucence), Corresponding author : Young-Jo Park yjpark87@kims.re.kr Tel : Fax : Ÿ Ÿ (photoluminescence)» (mechanical properties) y ƒ p œ m š y. wš LED š šz y /y / x Ÿ w yww w š ƒ ƒ w št wš. x r y y ƒ ( ) y xÿ w œ w û ey» w q»/ q Ÿ / w» w ƒ š. 3-13)» ü w w y yy xÿ ( ) y xÿ w š w». p, t y (SiAlON) xÿ ƒ š, w ¾ Ÿq ùkü ƒÿ š. 3-7,10-13) š v (Eu) v Ÿw k e y w œ w 503

2 504 Á zá Á Á Table 1. Nomenclature and Composition of Specimens z Si 3 N 4 (g) AlN(g) Al 2 (g) CaC (g) Eu 2 (g) β β β β1ex β1ex w» wš w. 2. x Si 6-z :Eu y t w k xÿ w w Si 3 N 4 (SN-E10, Ube industries, Ltd., d 50 =0.3 µm), AlN(grade B, H. C. Starck, d 50 =2~4.5 µm), Al 2 (AKP-30, Sumitomo Chemical, d 50 = 0.1~0.3 µm), CaC (99.9%, Kento Industries, Ltd.) Eu 2 (99.99%, Aldrich, nm ). y Eu ƒ y 0.04 š w, ƒ w 0.3 mol% w w. z 0.2, w ƒƒ r β1, β2, β3 ew. š β1 w CaO 1wt% 2wt% ƒw w w ƒƒ β1ex1, β1ex2 w (Table 1). yw w, g y³ w, ù» w 150 rpm, s p» w 200 rpm z g. yw z #100 w ƒ wš, w w 10 ƒw. 15 mm 1.2 yw e w x z 200 MPa 5 w þ x w ƒ ƒƒ 14 mm 4.5 mm x w. x ƒ» (BN:Si 3 N 4 =1:1) ƒ w. CaO CaC wƒ CO 2 yw w» w 900 C o w 1 w œ w w, 900 o C z 0.1 MPa ƒ n w w z 0.9 MPa w LtoH1800, LtoH1900, LtoH2000 x 5.0 MPa w 5MPa2000 x ww.» x ùk ü 4 m w. yw s Beckman coulter LS w d w, yw w d LECO Oxygen/ Nitrogen analyzer model e w. Rigaku D/Max 2200 w w, ƒ 90% w - v d w w š, 90% j w. 3. š 3.1. yw w e y yw (%TD) d Fig. 1 ùkü o C w β2(z=1.0) r e y ƒ ƒ w, 2000 C o β1(z=0.2) r ƒ w 97.5% d o C LtoH MPa2000 β1 Fig. 1. Measurement of (a) relative density and (b) weight loss of specimens sintered by various conditions. w wz

3 Ÿ β-sialon:eu v p xÿ e y 505 Fig. 2. XRD patterns of (a) normal scan and (b) slow scan with Si as a standard material. Specimens were sintered by LtoH2000 condition. w, β2 β3 0.9 MPa w 5.0 MPa ùkû.» ƒ Fig. 1(b) v w w., w ƒ β1 r» w ùkü w ƒ, β2 β3 r û» (0.9 MPa) ƒ j» ƒ š» (5.0 MPa) ƒ. k ù Pettersson SPS(m y ƒ ), HIP(š ƒ ) HP( ƒ ) p w w e yƒ ƒ w šwš. 14) w j» w Ekstrom yw k 1wt% Y 2 ƒw k w 1800 o C 93% w š šw. 15) Ÿ» w y Eu wt% ƒw, Y 2 w w ww» w e y» w. ù Fig. 1(a) 1800 o C β2 r 90%» w e wš. XRD w» 3 k x w y, Fig. 2 LtoH2000 XRD ql w. Fig. 2(a) z ƒw ƒ f» vj eƒ Fig. 3. XRD patterns of β1 specimens collected by (a) normal scan and (b) slow scan with Si as a standard material. ƒ w vp w. Fig. 2(b) ùkü r t t g gqw w vj e Bragg's Law w w Ekstrom w w r z w. 15) a(å) = z a c(å) = z c a w w z a c w w z c s³ w z β1, β2, β3 r ƒƒ 0.23, 0.94, 2.12 w ƒ. w r» 47«6y(2010)

4 506 Á zá Á Á Fig. 4. Measurement of (a) green density and (b) sintered density of specimens prepared by planetary milling(pm) and ball milling(bm). Specimens were sintered by LtoH1800 condition. w k x Fig. 3 XRD ql y w. Fig. 3 z 0.2 w β1 r β2 β3 r w w ùkü.,» XRD ql vj eƒ ew w z ùküš, ƒ û w LtoH1800 x sx w k w ƒ q. ù vj eƒ ew ü y Eu š» TEM w yw w e y ƒ β1 ƒ β3 r w w yw w LtoH1800 w. CIP x d w Fig. 4 ùkü. w x ƒwš β1 r 9%, β3 r 6% s ƒw. p, β1 r Ekstrom 15) w š 93% w 95% ƒ d y ƒ Eu 2 ƒ w ww q. w z s y» w., (PM) w (BM) š s» x ƒ ƒwš w q (Fig. 5)., β1 w yw ww, t yd w w Fig. 5. Particle size distribution of mixed powders prepared by planetary milling(pm) and ball milling(bm). w w 1.5%. z d ƒƒ 3.2% 3.9%, w w Si 3 N 4 AlN yƒ ƒ yd SiO 2 Al 2 ƒ w ƒ CaO ƒ e y e w 2000 o C x ƒ e y š Ÿ p w d β1 w CaO ƒw e y e w w. Hewett š w Ca-α-SiAlON yw CaO w CaO ƒw w wz

5 Ÿ β-sialon:eu v p xÿ e y 507 y ùkü., l y mw w ƒ ƒ w x., CaO ƒ w ƒ ƒ k ƒ ƒ w, 1800 C 96.4% o ƒ œ w e yƒ ƒ w. Acknowledgment 2009 LED. Fig. 6. XRD patterns of β1 specimens with- and without-cao addition sintered by LtoH1800 condition. w ƒ w. 16) β-sialon: Eu v p xÿ yw CaO s ww, CaOƒ ƒ β-sialon α-sialon x w» ƒ 1wt% 2wt% ww ƒƒ β1ex1, β1ex2 t»w (Table 1).» CaO ƒ r LtoH1800 w d w β1ex1 β1ex2 r ƒƒ 96.2% 96.4% CaO ƒ β1 r 95.0% s w. r (Fig. 6), q 2 x k w», CaO ƒ Ÿp w e š w j. 4. xÿ w LED qj x Ÿ + w r p w LED xw» w y v p x xÿ w ww. v v k xÿ (β- SiAlON:Eu) š e y» w., w œ j», s y w x w e, x 4 w 24 w ƒ., y ƒ Eu 2 x w w k 1800 o C 95% e REFERENCES 1. K. J. Choi, S. D. Jee, C. H. Kim, S. H. Lee, and H. K. Kim, Luminescence Characteristics of Mg 2+ Ba 2+ Co-doped Sr 2 SiO 4 :Eu Yellow Phosphor for Light Emitting Diodes, J. Kor. Ceram. Soc., 44 [3] (2007). 2. H. Gerard, B. Serge, and P. Mark, White LED for Backlight with Phosphor Plates, US patent , Philips lumileds lighting Company, LLC (2007). 3. J. W. H. van Krevel, J. W. T. van Rutten, H. Mandal, H. T. Hintzen, and R. Metselaar, Luminescence Properties of Terbium-, Cerium, or Europium-Doped α-sialon Materials, J. Solid State Chem., (2002). 4. R. -J. Xie, M. Mitomo, K. Uheda, F. F. Xu, and Y. Akimune, Preparation and Luminescence Spectra of Calcium- and Rare-Earth (R=Eu, Tb, and Pr)-Codoped α-sialon Ceramics, J. Am. Ceram. Soc., 85 [5] (2002). 5. R. -J. Xie, N. Hirosaki, K. Sakuma, Y. Yamamoto, and M. Mitomo, Eu 2+ -doped Ca-α-SiAlON: A Yellow Phosphor for White Light-emitting Diodes, Appl. Phys. Lett., , (2004). 6. R. -J. Xie, N. Hirosaki, M. Mitomo, Y. Yamamoto, T. Suehiro, and K. Sakuma, Optical Properties of Eu 2+ in α-sialon, J. Phys. Chem. B, (2004). 7. N. Hirosaki, R. -J. Xie, K. Kimoto, T. Sekiguchi, Y. Yamamoto, T. Suehiro, and M. Mitomo, Characterization and Properties of Green-emitting β-sialon:eu 2+ Powder Phosphors for White Light-emitting Diodes, Appl. Phys. Lett., (2005). 8. Y. Q. Li, J. E. J. van Steen, J. W. H. van Krevel, G. Botty, A. C. A. Delsing, F. J. DiSalvo, G. de With, and H. T. Hintzen, Luminescence Properties of Red-emitting M 2 Si 5 N 8 :Eu 2+ (M=Ca, Sr, Ba) LED Conversion Phosphors, J. Alloy Comp., (2006). 9. K. Uheda, N. Hirosaki, Y. Yamamoto, A. Naito, T. Nakajima, and H. Yamamoto, Luminescence Properties of a Red Phosphor, CaAlSiN 3 :Eu 2+, for White Light-emitting Diodes, Electrochem. Solid-State Lett., 9 [4] H22-H25 (2006). 10. R. -J. Xie and N. Hirosaki, Silicon-based Oxynitride and Nitride Phosphors for White LEDs - A Review, Sci. Tech. Adv. Mater., 8, (2007). 47«6y(2010)

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