White Lighting (Illumination) with LEDs - UVapedro/optoele/LEDs/RumpSessionIII.pdf · Up to 5 W...

11 Copyright (c) Lumileds Lighting LLC Company ConfidentialCopyright (c) Lumileds Lighting LLC Company Confidential

White Lighting (Illumination) with White Lighting (Illumination) with LEDsLEDs

Werner GoetzWerner GoetzLumileds LightingLumileds Lighting

22Copyright (c) Lumileds Lighting LLCCopyright (c) Lumileds Lighting LLCFifth International Conference on Nitride Semiconductors, ICNS-5

Nara, Japan, May 25-30, 2003

Outline

•• Lumileds’ power LED platformLumileds’ power LED platform•• Monochromatic Monochromatic •• WhiteWhite

•• Illumination with Illumination with LEDsLEDs•• Light Source Criteria,Light Source Criteria,•• Options,Options,•• and Issuesand Issues

•• Next stepsNext steps•• Conclusion / OutlookConclusion / Outlook

LED light fixture – 12 Luxeon LEDs, 0.24 klm



Lumileds’ Power LEDs - I

•• FlipFlip--chip chip LEDs LEDs (III(III--V Nitrides)V Nitrides)•• 0.1 0.1 –– 4 mm4 mm22 die areadie area•• 2x extraction efficiency gain2x extraction efficiency gain•• Efficient heat removalEfficient heat removal

•• Power PackagePower Package•• Low thermal resistanceLow thermal resistance

(4 (4 -- 14 K/W)14 K/W)•• Up to 5 W input powerUp to 5 W input power•• RadiationRadiation--resistant resistant

encapsulants

Silver reflectorGaN

Sapphire

Light

Wire bond Silicon submount

Gold Wire Solder Connection

Cathode Lead

Plastic Lens

Silicone Encapsulent

InGaN Semiconductor Flip Chip

encapsulantsHeatsink Slug Silicon Sub-mount Chip

with ESD Protection



Lumileds’ Power LEDs - II

•• WallWall--Plug EfficiencyPlug Efficiency•• ~20 % for blue~20 % for blue•• Decreases for Decreases for

longer wavelengthlonger wavelength

•• Input powerInput power•• 1 W and 5 W1 W and 5 W

•• Power / Flux (5 W)Power / Flux (5 W)•• >1 W for blue>1 W for blue•• >200 lm for green>200 lm for green

420 440 460 480 500 520 540

8

12

16

20

24

28

WPE ~18 %, λ ~475 nm

J = 75 A/cm2

(pulsed)T

J = 25°C

Chip: 1 x 1 mm2

WPE ~11 %, λ ~530 nm

WPE ~14 %, λ ~500 nm

WPE ~22 %, λ ~450 nm

WPE ~26 %, λ ~430 nm

Peak Wavelength (nm)

LumiledsIII-NitridePower LEDs

Wal

l-Plu

g Ef

fici

ency

(%

)



White Power LEDs

4000

4500

5000

5500

6000

-100 0 100

Viewing Angle (deg)

CC

T (K

)

Conventional

Luxeon

Reflector Cup

Die Attach Epoxy

LED Die

Submount Die

Phosphor Granules•• Conformal phosphor Conformal phosphor coatingcoating

•• Smaller source size Smaller source size •• Improved angular Improved angular

“color” uniformity“color” uniformityPhosphor layer LEDLuxeon

“Conventional”, slurry deposited LED



White Light Criteria: LEDs I 70 % “Lumen Maintenance” at 50k hours70 % “Lumen Maintenance” at 50k hours

Incandescent: Incandescent: ~1k hours~1k hoursFluorescent:Fluorescent: ~10k ~10k –– 20k hours20k hours

0%

20%

40%

60%

80%

100%

120%

0 2000 4000 6000 8000 10000 12000 14000Time (hrs)

Rel

ativ

e L

ight

Out

put

Lighting Research Center - Sept 2002

Luxeon

5 mm white

•• LifetimeLifetime



White Light “Criteria”: LEDs II

~30 and ~150 lm (~30 and ~150 lm (Luxeon Luxeon 1 and 5 W)1 and 5 W)Incandescent: Incandescent: 110 110 –– 1 1 klmklm (15 and 60 W bulbs)(15 and 60 W bulbs)Fluorescent:Fluorescent: 150 150 –– 3 3 klmklm ( 4 ( 4 –– 32 W tubes)32 W tubes)

20 20 -- 38 lm/W 38 lm/W Incandescent: Incandescent: 7 7 –– 15 lm/W (to 25 lm/W for halogen)15 lm/W (to 25 lm/W for halogen)Fluorescent:Fluorescent: 35 35 –– 100 lm/W100 lm/W

0.001

0.01

0.1

1

10

100

1000

1960 1970 1980 1990 2000 2010

Year

Flux

/Pac

kage

(lum

ens)

Indicator LEDs

Luxeon TM

20 x / decade

•• EfficiencyEfficiency

•• Flux per Flux per packagepackage



White Light “Criteria”: LEDs IIIDependent on white LED technologyDependent on white LED technology

Incandescent: Incandescent: CCT limited to < ~3200 KCCT limited to < ~3200 KFluorescent:Fluorescent: RRAA “artificially” high“artificially” high

x

y

640630

600

590

530520

510

500

460470

480

490

450

10,000 K

5,000 K

3,300 K2,500 K

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

540

610

Three color triangle

Blue LED

YAGPhosphor

Blue LED+

phosphor

Planckian Locus

Incandescent

•• CIE DiagramCIE Diagram-- On or close to On or close to ““PlanckianPlanckian” locus” locus

-- Range of color Range of color temperaturestemperatures

-- High color High color rendition (Rrendition (RAA))

Fluorescent bulb, Ra = 83

0

0.005

0.01

0.015

0.02

0.025

400 450 500 550 600 650 700 750 800nm

rad.

flux

, a.u

.

0.0

0.2

0.4

0.6

0.8

1.0

1.2

rad.

flux

, a.u

.black body 3600 K

fluorescent, CCT=3600 K

Ra = 83



Some White LED Options

•• Direct Direct –– RGB RGB LEDsLEDs•• Potentially highest efficiencyPotentially highest efficiency•• Very large color gamutVery large color gamut•• Tunable white pointTunable white point

•• Blue LED + yellow phosphorBlue LED + yellow phosphor•• SimpleSimple•• Decent color rendering (RDecent color rendering (Raa ~75)~75)

•• UV LED + RGB phosphorsUV LED + RGB phosphors•• White point determined by phosphors White point determined by phosphors

onlyonly•• Excellent color rendering

RGB LEDs

Blue LEDs + yellow phosphor

UV LED + RGB phosphors

Excellent color rendering



White LED IssuesLuxeon Performance (350 mA, Tj = 25C)

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

430 460 490 520 550 580 610 640

Peak Wavelength (nm)

Exte

rnal

Qua

ntum

Eff

icie

ncy•• RGB RGB LEDsLEDs

•• Green LED efficiencyGreen LED efficiency•• Temperature stability ofTemperature stability of

LEDsLEDs depends on colordepends on color•• Different degradationDifferent degradation

trendstrends

•• LED + Phosphor(s)LED + Phosphor(s)•• Efficiency of pump LED Efficiency of pump LED •• Reduced extraction efficiencyReduced extraction efficiency•• “Quantum deficit” is fundamental“Quantum deficit” is fundamental•• Blue LED + YAG phosphor: High CCT and limited color Blue LED + YAG phosphor: High CCT and limited color

renderingrendering•• UV LED + RGB phosphor: Degradation of organic UV LED + RGB phosphor: Degradation of organic

encapsulantsencapsulants

InGaN

AlInGaP

EyeSensitivity



Lumileds’ “Warm White”•• Blue LED + yellow and red phosphorBlue LED + yellow and red phosphor

0.45

0.46

0.47

0.48

0.49

0.5

0.51

0.52

0.53

0.54

0.55

0.17

0.18

0.19 0.

2

0.21

0.22

0.23

0.24

0.25

0.26

0.27

u'

v'

6000K

5000K

4000K

3500K3000K

single phosphor

dual phosphor

400 500 600 700 800Wavelength (nm)

400 500 600 700 800Wavelength (nm)

Wavelength (nm)

Wavelength (nm)

400 500 600 700 800Wavelength (nm)

400 500 600 700 800Wavelength (nm)

Wavelength (nm)

Wavelength (nm)

Dual phoshpor

Singlephoshpor

CCT = 2880 KRa = 91.9

“Black Body”CCT = 2880 K

•• RRaa >90, R>90, R99 >60>60•• Tint free: 2800 Tint free: 2800 –– 4000 K4000 K•• 20 20 –– 25 lm/W25 lm/W

CCT = 3800 KRa = 94.4

Planckianlocus



Sunlight Spectrum D65

•• “Light box” with RGB and phosphor converted “Light box” with RGB and phosphor converted LEDsLEDs

0.0

0.2

0.4

0.6

0.8

1.0

380 430 480 530 580 630 680 730

Wavelength (nm)

Rel

ativ

e In

tens

ity

Luxeon Lightbox • CCT: 6705 K• CRI: Ra,8 = 95.6 %

Ra,14 = 94.4 %• Total Flux: 547 lm• Input Power: 48.9 W

D65 Spectrum

•• Excellent renditionExcellent renditionof daylight spectrumof daylight spectrum

•• Color uniformityColor uniformitydu’v’ du’v’ ≤ 0.0050.005



Conclusion / Outlook•• TodayToday

•• >150 lm, 30 lm/W, 50k hours>150 lm, 30 lm/W, 50k hours•• LEDs LEDs are very efficient in distributing light (small source size)are very efficient in distributing light (small source size)•• All white LED options have potential strengthsAll white LED options have potential strengths•• Cost ($/lm) is 100 x Cost ($/lm) is 100 x

•• VisionVision

Roland Haitz2003

1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015

Year

Flux

/ LE

D

(lm) a

nd C

ost

($/lm

)

+20x / Decade

Flux / Lamp (lm)

-10x / Decade

Cost / Lumen ($ / lm)



D65 “Light box”

Date post:	28-Sep-2018
Category:	Documents
Upload:	doanhuong
View:	213 times
Download:	0 times

White Lighting (Illumination) with LEDs - UVapedro/optoele/LEDs/RumpSessionIII.pdf · Up to 5 W...

Documents