Journal of the Korean Ceramic Society Vol. 47, No. 6, pp. 503~508, 2010. DOI:10.4191/KCERS.2010.47.6.503 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, 641-831, Korea *Electro Materials and Device Center, Samsung LED, Suwon 443-743, 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 (2010 9 27 ; 2010 10 18 ; 2010 10 26 ) 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 E-mail : yjpark87@kims.re.kr Tel : +82-55-280-3356 Fax : +82-55-280-3392 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
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) β1 0.2 94.12 0.95 2.36-2.57 β2 1.0 80.94 4.73 11.77-2.57 β3 2.0 64.55 9.43 23.46-2.56 β1ex1 0.2 92.47 0.93 2.32 1.75 2.53 β1ex2 0.2 90.88 0.92 2.28 3.45 2.48 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, 1.0 2.0 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-13320 w d w, yw w d LECO Oxygen/ Nitrogen analyzer model 631-800-100 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. 1900 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. 2000 o C LtoH2000 5 MPa2000 β1 Fig. 1. Measurement of (a) relative density and (b) weight loss of specimens sintered by various conditions. w wz
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 2 2.6 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) = 7.603 + 0.0297z a c(å) = 2.907 + 0.0255z 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)
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. 3.2. 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. 3.3. 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
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