목차 1. 형광체종류및특성 2. Light Emitting Diode Phosphor 2

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1 형광체 (Phosphor) 한밭대학교신소재공학과박인용 Phosphor 1

2 목차 1. 형광체종류및특성 2. Light Emitting Diode Phosphor 2

3 1. 형광체의종류및특성 1.1 형광체 (Phosphors) 란? 1.2 발광과정과형광체의구조 1.3 형광체의 Size 효과 1.4 형광체분말의합성법 1.5 형광체분말의용도 Phosphor 3

4 1.1 형광체 (Phosphors) 란? Energy Converter : 여러가지에너지를가시광선으로바꾸어주는 무기또는유기화합물 Luminescence Visible light Electron beam UV light X-ray Phosphor Host Lattice Activators Sensitizer Phosphor 4

5 에너지원에따른형광체의분류 1 Photoluminescence ( 광발광 ) : electromagnetic (often UV) radiation Florescent Lamp, PDP, LED 2 Cathodoluminescence ( 음극선발광 ) : energetic electrons CRT, FED 3 Electroluminescence ( 전계발광 ) : electric field ELD 4 Chemiluminescence : chemical reaction 5 Triboluminescence : mechanical energy Phosphor 5

6 1.2 발광과정과형광체의구조 Excitation ( 여기 ) S H A 발광 에너지전이 : relaxation ( 완화 ) A : Activator (luminescence center) H : Host (holding the activator ions) S : Sensitizer (increasing the luminescent efficiency) Phosphor 6

7 Ene ergy Step 1 Host Lattice Step 2 Step 3 Step 4 Activator Step 1 : Absorption 여기원으로부터에너지의흡수 Step 2 : Excitation 활성제중심내에서에너지준위의여기 Step 3 : Relaxation Excitaion r Emission Relaxation process s 여기상태의완화 Step 4 : Emission 기저상태로의천이에기인한광방출 r 0 Ground state Effective radius (r) Phosphor 7

8 형광체의구조 1 Activator ( 활성제, luminescence center) : - 실제로빛을내는이온. - 기저준위와여기준위사이의전이에의해에너지를흡수또는방출. - 방출에너지의형태는전자기파의방출 (radiation transition) 과열방출 (non-radiative transition) 2 Host ( 모체, holding the activator ions) : - activator 이온을잡아주는역할. - Host의영향매우큼. 효율이높은형광체개발은 host에의한에너지흡수와흡수된에너지가얼마나효율적으로 activator로이동 (energy transfer) 하느냐가중요 Phosphor 8

9 3 Sensitizer ( 증감제, increasing the luminescent efficiency) : - 자체는빛을흡수, 방출하지않으나, activator 의광효율을 증가시키는역할. ( 예 ) 모체의결정성증가, 모체의전도성향상으로 activator 로의 energy transfer 효율증가, activator 의 doping 효율 증가등의연구가진행중. Luminescence killer : - 주로이차상이나전이금속과같은불순물을지칭. - Host 또는 activator가흡수한에너지가전이되는사이에 luminescence killer에의해그에너지가흡수되어 phonon ( 음파 ) 의형태로방출. Phosphor 9

10 색좌표 CIE 1931 Chromaticity Diagram 자연의모든색은편자안의점들로표현된다. 색도표상에밝기는표시되지않는다. x y = = X X + Y + Z Y X + Y + Z Phosphor 10

11 CIE 1976 Chromaticity Diagram u' = - 2x 4x + 12y + 3 v' = - 2x 9y + 12y + 3 Phosphor 11

12 1.3 형광체의 Size 효과 Semiconductor : Exciton radius Exciton : 외부에너지에의하여형성된 e - 과 h + 쌍을이루고있는상태 Semiconductor 의경우 exciton 의지름에의존하여 quantum size effect를나타냄 보통 1 10nm 범위를가짐 Semiconductor의 quantum size effect를형성하기위해서는 1 10nm 크기를가진 nanoparticle이필요 Quantum Size Effect of Semiconductor Ex) CdSe Phosphor 12

13 Ionic Crystal Size 감소 : 정전기적에너지감소용해도증가평균결합길이증가 Insulator particles quantum size effect를나타내기보다는 surface chemistry에변화를줌 Optical Property Change Bulk phosphors by the chemical composition Quantum dot phosphors by changing the particle size by the chemical composition Phosphor 13

14 efficiency Lumin nescence Variation of Luminescence Efficiency ZnS nanophosphor Surface-related non-radiative recombination NANO Increase of activator efficiency due to quantum confinement Decrease of efficiency due to surface recombination BULK Bulk efficiency Phosphor particle size (nm) B. R. Chakraborty et al, Nanotechnology, 16, 1006 (2005). Phosphor 14

15 1.4 Synthesis of Phosphor Powders Solid State Process - Solid State Reaction - Mechanochemical Process Wet Chemistry - Sol-Gel Process - Hydrothemal Synthesis - Solvothermal Synthesis - Precipitation (Homogeneous, Coprecipitation) Vaporization - Combustion Synthesis - Glycine Nitrate Process Phosphor 15

16 1.5 형광체분말의용도 각종디스플레이소자용형광체 CRT Phosphor Blue Green Red ZnS:Ag,Al ZnS:Cu,Al Y 2 O 2 S:Eu (Cathode Ray Tube) Lamp Phosphor Blue Green Red White (SrCaBaMg) 5 (PO 4 ) 3 Cl:Eu LaPO 4 :Ce,Tb Y 2 O 3 :Eu Ca 10 (PO 4 ) 6 FCl:Sb,Mn (Fluorescent Lamp) PDP Phosphor Blue Green BaMgAl 10 O 17 :Eu Zn 2 SiO 4 :Mn Red (Y,Gd)BO 3 :Eu (PDP) X-Ray Phosphor Blue CaWO 4 Green Gd 2 O 2 S:Tb UV (Y,Sr)TaO 4 :Nb (X-Ray Intensifying Screen) Phosphor 16

17 형광체의여기원 형광체종류 여기원 응용분야 Photo- UV (254 nm) Fluorescent Lamp luminescence VUV (147 nm) PDP Cathodoluminescence Electroluminescence High Voltage e-beam (25kV) Low Voltage e-beam (100V이하) ( V) High Voltage AC Field Low Voltage DC CRT VFD FED ELD LED Phosphor 17

18 PDP 용형광체의특성 CIE색좌표상대발광색형광체방사 X Y 효율 1/10 잔광시간 기호 Red (Y,Gd)BO 3 :Eu Y 2 O 3 :Eu ms 3ms D E Green Zn 2+ 2 SiO 4 :Mn ms B BaAl 12 O 19 :Mn ms C Blue BaMgAl 14 O 23 :Eu <1ms A Phosphor 18

19 d b a. (Y,Gd)BO 3 :EU (RED) b. Zn 2 SiO 4 :Mn (GREEN) c. BaAl 12 O 19 :Mn (GREEN) d. BaMgAl 14 O 23 :Eu(BLUE) a c RGB 형광체의 Quantum Efficiency (a) (Y,Gd)BO 3 :Eu 3+ (b) Zn 2 SiO 4 :Mn 2+ (c) BaAl 12 O 19 :Mn 2+ (d) BaMgAl 14 O 23 :Eu 2+ Phosphor 19

20 PDP 용형광체의발광스펙트럼 Phosphor 20

21 Nichia PDP Phosphor ( NP # Composition S.G. NP- 107 NP- 200 NP- 203 NP- 205 NP- 340 NP- 360 NP- 361 Emission Peak (nm)/color Band Width (nm) BaMgAl 10 O 17 :Eu Blue 53 Zn 2 SiO 4 :Mn Green 42 YBO 3 :Tb Green Line BaAl 12 O 19 :Mn Green 35 Y 2 O 3 :Eu Red Line (Y,Gd)BO 3 :Eu Red Line YBO 3 :Eu Red Line S.G. : Specific Gravity Phosphor 21

22 VFD 용형광체 [ 형광체의조성에따른발광개시전압및 Peak 파장 ] 발광색 형광체의조성 발광개시전압 V th [V] 발광 PEAK 파장 [nm] Green ZnO : Zn Blue ZnS : Cl + In 2 O Yellowish Green ZnS : Cu,Al + In 2 O Greenish Yellow (Zn 0.50,Cd 0.50 )S : Ag,Al + In 2 O Yellowish Orange (Zn 0.40,Cd 0.60 )S : Ag,Al + In 2 O Orange (Zn 0.30,Cd 0.70 )S : Ag,Al + In 2 O Reddish Orange (Zn 0.22,Cd 0.78 )S : Ag,Al + In 2 O In 2 O 3 : 첨가제로써도전성물질. Phosphor 22

23 Intensity of Emission Re elative VFD 용형광체발광특성 100% Peak Wavelength (lp) Wavelength (nm) Phosphor 23

24 2. Light Emitting Diode 2.1 White LED 구현방법 2.2 White LED 용형광체의합성및특성 2.3 LED 시장전망 Phosphor 24

25 LED 의발전역사 Phosphor 25

26 LED 성능발전 Phosphor 26

27 미래형 LED Phosphor 27

Energy Gap (ev) 2.1 White LED 구현방법 LED 재료 6.0 5.0 4.0 3.0 2.0 1.

28 Energy Gap (ev) 2.1 White LED 구현방법 LED 재료 GaN AlN Al x Ga 1-x N 계 : < 364 nm GaN(cubic) Direct bandgap Indirect bandgap ZnS MgS MgSe SiC AlP ZnSe GaP InN AlAs GaAs In x Ga 1-x N 계 : >364 nm CdSe InP -UV Blue Green(525nm) Si Ge Sapphire Lattice Constant (A ) Phosphor 28

29 백색 LED 를구현하기위한제작방법 LED-based and LED-plus-phosphor based approaches for white light sources implemented as di-, tri-, and tetrachromatic sources. E. F. Schubert and J. K. Kim, Science, 308, (2005). Phosphor 29

30 White LED 구현방법 R,G,B-LED Color rendering index ( 연색지수 ) : 광원이얼 마나색채를태양광및완전복사체등과같은 기준광에가깝게재현하는지를평가하는계수 3개의 LED 사용각각의 LED 제어어려움 B-LED + Yellow Phosphor 상대적낮은발광효율, 낮은 CRI. 전류밀도에따라 CRI 변화 : 태양광에가까운백색광을얻기가어렵다. UV-LED + R,G,B Phosphors 고전류하에서사용가능높은효율, 높은 CRI, 색온도조절가능다른전류밀도에서도높은색채안정성색감우수 : 연구가장활발형광체조합의복잡성, 높은효율의적색형광체결여 Phosphor 30

31 Phosphor based white LEDs Phosphor 31

32 B-LED + Yellow Phosphor Phosphor 32

33 2.2 White LED 용형광체의합성및특성 Table. Comparison of synthesis methods in terms of the particle sizes, morphology control, required temperatures, cost and limitations. From MSE R, 71, 1-34 (2010). Phosphor 33

34 Table. Methods for preparation of YAG:Ce. From MSE R, 71, 1-34 (2010). Phosphor 34

35 EL spectra of the white LEDs using both InGaN-based blue-leds and (a) Y 3 Al 5 O 12 :Ce 3+, Pr 3+ phosphors with varying the amount of Pr 3+ and (b) yellow emitting (Y 1-x Tb x ) Y 3 Al 5 O 12 :Ce 3+ phosphors with varying the amount of Tb 3+. From J. Lumin. 126 (2007) 371. Phosphor 35

36 Table. Spectroscopic and structural properties of Ce 3+ -doped garnets. J.L. Wu, G. Gundiah, and A.K. Cheetham, Chem. Phys. Lett. 441 (2007) 250. Phosphor 36

37 SEM images of YAG:Ce prepared by (a) co-precipitation, (b) sol gel, (c) combustion, (d) solid-state synthesis. From Mater. Sci. Eng. B 106 (2004) 251. Phosphor 37

38 Emission spectra of 4 mol% Ce-doped YAG prepared by (a) combustion, (b) sol gel, (c) co-precipitation, (d) solid-state synthesis [120]. From Mater. Sci. Eng. B 106 (2004) 251. Phosphor 38

39 Table. Characteristic of some phosphors other than YAG:Ce for pc- WLEDs excited by blue-led chips (nitrides and oxynitrides are not included). Phosphor 39

40 EL spectra of white LEDs using (a) 460 nm chip and (b) 405 nm chip and (c) a yellow LED using 380 nm chip measured under a forward bias of 20 ma. From Appl. Phys. Lett. 90 (2007) Phosphor 40

41 Normalized PL and PLE spectra of Sr 3 SiO 5 :Ce 3+,Li +. From Appl. Phys. Lett. 90 (2007) Phosphor 41

42 Table. Summary of some single-phased white-emitting phosphors applicable for pc-wleds. Phosphor 42

43 황색광전환세라믹소재특허등록현황 회사특허광전환소재 Nichia US (Jul 29, 1996) YAG:Ce OSRAM US (Jul 23, 1999) TAG:Ce GE US (Nov 30, 1998) Ba-orthosilicate OSRAM WO 02/11214 (Jul 28, 2000) (Sr,Ba)-orthosilicate Toyoda Gosei/LWB/Tridonic US (Dec 28, 2000) US (Dec 28, 2000) (Ca,Sr,Ba)-orthosilicate (Ca,Sr,Ba)-orthosilicate Phosphor Technology WO 04/ (May 17, 2003) (Ca,Sr,Ba)-orthosilicate Intermatix Corp. US (Sep 11, 2007) M-orthosilicate(:Eu, halide) KRICT US (May 16, 2006) KR (Jan 10, 2007) Sr 3 SiO 5 :Eu (Sr,Ba,Mg)-orthosilicate 출처 : 백색 LED 용형광체기술분석, Mar 디스플레이뱅크 Phosphor 43

44 2.3 LED 시장전망 세계각국의 LED 조명지원현황 중국 호주 조명의 30% 를 LED 로대체해연간 580 억 KWh 절약하는 LED 프로젝트추진! 2010~2012년까지백열전구판매중지법안추진! 유럽 2012 년 8 월부터 LED 로차량용낮라이트의무화! 미국 2020 년까지조명의 50% 를 LED 로보급! 한국 2012 년까지 LED 조명비중을 30% 로향상! Phosphor 44

45 Evolution of luminous efficacy performance of white light sources. Commercially available high-power LED performance is indicated by the points along the solid blue curve. From J. Display Technol. 3 (2007) 160. Phosphor 45

46 Projected cost of light. Arrows show the present cost of ownership for incandescent and fluorescent lighting. From Proc. IEEE 93 (2005) Phosphor 46

47 LED 원가분석및핵심부재산업동향 그림. LED Package 의주요부재 그림 SMD 패키지의원가구조 Phosphor 47

48 국내 LED 시장규모전망 LED 산업매년평균 45% 고성장예상 -2013년정부 13조투자 LED 시장전망 - LED성장성 è 2008 ~ 2011년사이성장 Peak Phosphor 48

49 전세계 LED LCD TV 시장규모전망 출처 : LED LCD TV 업체별로드맵및시장전망 2009 년 12 월, 디스플레이뱅크 Phosphor 49

50 신규성장산업 ( 지속성장 ) CCFL대비 LED특성환경적측면 CCFL LED 수은 (Hg) 사용친환경 ( 유해물질無 ) 수명 (hrs) 30, ,000 소비전력 (40'' 기준 ) 170W 100W 색체재현 최고 90% 100% 이상가능 BLU 용 LED 시장전망 (LED 단품기준 ) ,194 6,735 12,760 22,605 (Stategies Unlimited 2006, 단위 : 억원 ) Phosphor 50

2009 년 LED LCD TV 브랜드별판매지역현황 http://www.displaybank.

51 2009 년 LED LCD TV 브랜드별판매지역현황 Phosphor 51

52 글로벌 LED 산업지원전망 LED 가로등 홍콩최대규모의 LED 옥외광고 Phosphor 52

53 농가보급형 LED 광처리장치 LED< 발광소자 > 조명받고인삼이 ' 무럭무럭 ' 조선일보사회, IT/ 과학 ( 목 ) 오전 3:26 Phosphor 53

54 Thank you!

백색 LED를 사용한 조명용 광원의 설계 및 분석

백색 LED를 사용한 조명용 광원의 설계 및 분석 1879 년백열등 1938 년형광램프 1964 년 HID 램프 1990 년대초 ( 신광원 ) 무전극방전램프 LED 램프 에너지절약기술개발활성화대두 Solid-State Lighting 고효율, 장수명, 고연색성, 에너지및자원절약 쾌적성, 안전성, 지구환경보호, 다양한색가변가능 1000 0.3 x CIE 비시감도곡선 (CIE) 발광효율