Light Emitting Diodes for Solid State Lighting

1

Klaus Streubel

Light Emitting Diodesfor Solid State Lighting

for SSL – Romme, Sweden 12.3.2010 | Page 2

Outline

Osram at a Glance

Motivation

Advances in LED Technology

Solid State Lighting

OLED: next generation LED

2


OSRAM at a Glance

Employees:More than 43,500

– OSRAM: one of the world's two leading lighting manufacturers (headquarters: Munich)

– Trademark registration: on April 17, 1906 at thethen Imperial Patent Office in Berlin

– Founded on July 1, 1919 by the merger of the incandescent lamp manufacturing activities of AEG, Siemens & Halske AG and Deutsche Gasglühlicht-Anstalt (Auer-Gesellschaft)

Production:46 factories in 17 countries

Turnover:EUR 4.6 billion

Group profit:EUR 401 million

R&D:6 % of sales

The art project SEVEN SCREENS at OSRAM headquartersin Munich – a project developed in cooperation with OSRAMLight Consulting - shows that the OSRAM brand is 102 yearsyoung. 700,000 high-power RGB LEDs (16 mio different colours possible) have been installed on the masts and can be controlled via fiber optic cable from a central computer room.

FY 2008


OSRAM - Part of the Industry Sector of Siemens

DriveTechnologies

IndustrySolutions

BuildingTechnologies OSRAM MobilityIndustry

Automation

Energy HealthcareFossil Power GenerationRenewable EnergyOil & GasEnergy ServicePower TransmissionPower Distribution

Imaging & ITWorkflow & SolutionsDiagnostics

Drive TechnologiesIndustry AutomationBuilding TechnologiesMobilityLighting (OSRAM)Industry Solutions

Divisions

Siemens is a global powerhouse in electronics and electricalengineering, operating in the industry, energy and healthcare sectors.

Industry

3


OSRAM Activities

LED Systems

Opto Semi-conductors

Display / Optic(DO)

AutomotiveLighting (AM)

Consumer Lighting

Low PressureDischarge (LPD)

High PressureDischarge (HPD)

Electronics &Controls (EC)

Luminaires

Special Lighting

Professional Lighting

Halogen, CFLLED Retrofit

LEDs, OLEDs,Laser, IR

PL SP CL OS

L E DL E D L E D

L E D

L E DL E D

L E D


Osram: Driving Innovation

✔

German "President's Prize for Technology and Innovation"

2007

✔red dot design award 2008

Emmy Award 2007

Foto: Mark D

avis/Mathew

Imaging

“Oscar” Academy Award 1983, 1986

✔✔

German Sustainability Prize 2008

✔

4


LEDs for General Lighting

• Highly efficient

• Long lifetime

• Small & Rugged

• Mercury free

• Instand on, dimmable

• Directional emission

• All colors available

• ….

Many rational arguments:


LEDs for General Lighting

Emotion

5


0

5

10

15

20

2005 2010 2015 2020

Billion €

Year

* OSRAM estimation, only general lighting

Conventional light sources:stable, slighty decreasing market

Total market for light sources

9''10''7

12''9

15''9

LED components*:strong market growth

LED is driver for future growth of the lighting market


…Efficiency

• Lighting accounts for 19% of global electricity consumption

• 2651 TWh were used for lighting in 2005 (=consumption of Japan and China)• It would be technically feasible to save about 50% of this energy• Then, 460 Million Tons of CO2 would not be emitted into the atmosphere

6


Efficiency of High Brightness LEDs

0%

10%

20%

30%

40%

50%

60%

350 400 450 500 550 600 650 700

Wavelength (nm)

Exte

rnal

Effi

cien

cy

Dat

ensa

mm

ler I

nGaN

u In

GaA

lP E

ffizi

enz.

xls

InxGa1-xN

(AlxGa1-x)0.52In0.48P


1E-5 1E-4 1E-3 0.01 0.1 1 101E-5

1E-3

0.1

10

1E-5 1E-4 1E-3 0.01 0.1 1 100.0

0.2

0.4

0.6

0.8

1.0

optic

al o

utpu

t pow

er [a

.u.]

IQE

[a.u

.]

current density [kA/cm2]

Defects:I∝n1

Radiative:I∝n2

Auger:I∝n3

Auger model withliterature coefficent

Auger Loss in Visible LEDs

Karpov (STR)

• Non-radiative losses proportional to n³ Signature of Auger• Auger model with coefficient from literature fits experimental data

7


Thin-Film Process Flow

GaAs GaAs GaAs

GaAs

Ge Ge

Ge

Sapphire

Sapphire Sapphire Ge

Sapphire

Ge

Sapphire

AlGaInP

InGaN

Epitaxy dry etching metalization soldering substrate removal

Epitaxy metalization soldering laser lift-off surface roughening


Thin-Film – A new LED Platform

InGaAlP InGaN AlGaAs

High efficiency

Novel possibilitiesfor chip designs Surface

emission

Ideal for 2D chip arrays

Scalable area

8

for SSL – Romme, Sweden 12.3.2010 | Page 15Top view

Advanced Thin-Film Chip Designs

Conductive carrier

np

Cross sectional view

Conductive carrier

np

Cross sectional view

Luminance @ 1,4 A

Linearity

n-contactAbsorption vrs.

Series resistance

Luminance

Top viewLuminance @ 2,8 A

Standard ThinGaN ThinGaN UX:3


R&D 1mm Power ThinGaN blue and green

• 1mm² chip @440 nm, Golden Dragon+ • 1mm² chip @532 nm, Golden Dragon+

Advanced Package: 643 mW

Advanced Package Blue: 643 mW; Vf= 3.24 V, WPE = 57%

J. Baur et al.: IWN08M. Peter et al: IWN08

0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5

I [A]

Ie[W

]

601,4 mW@ 350 mA

Driving Current [mA]

Lum

inou

s Fl

ux Φ

v [lm

]

0

20

40

60

80

100

120

140

160

180

0 200 400 600 8000

20

40

60

80

100

120

140

160

180

200

Lum

inou

s Ef

ficac

y [lm

/W]

3199 mW@ 3 A

1966 mW@ 1,4 A

90 lm/W

109 lm

9


R&D 1mm² Power ThinGaN white • 1mm² chip, CLC Ultra White, Golden Dragon+

(CCT = 5000K)• 1mm² chip, CLC, Golden Dragon+

(CCT=3000K, Ra=80)

Advanced Package White: 155 lm; 136 lm/W; 3.24 V; 5000 KJ. Baur et al.: IWN08

M. Peter et al: IWN08

88 lm

74 lm/W

Lum

inou

s Fl

ux Φ

v [lm

]

Lum

inou

s Ef

ficac

y [lm

/W]

0

20

40

60

80

100

120

140

160

0 100 200 300 400 500 600 700 800

Current (mA)

0

20

40

60

80

100

120

140

160

Current [mA]

0

50

100

150

200

250

300

350

0 200 400 600 800 1000 1200 14000

20

40

60

80

100

120

140

160

Lum

inou

s Fl

ux Φ

v [lm

]

Lum

inou

s Ef

ficac

y [lm

/W]

114 lm/W

129 lm

263 lm

73 lm/W

88 lm

74 lm/W


Generation of Light and Heat

Chip: 1 x 1 mm²Operation: 1 A @ 3.2 VEfficiency: 40%Total power: 3.2 WEmitted: 1.3 WHeat: 1.9 W

1mm

Power Density: 1.9.106 W/m²

10


Innovative Package Development

TOPLED®

2 lm 90mW@20mA single chip

white

OSTAR®

100-1000lm 10 - 50W

multi chip30 lm 1,4W

@350mA singlechip white10 lm 250mW

@200mA single chipwhite

Advanced Power TOPLED®

Golden Dragon®

Power TOPLED®

3 lm 140mW@30mA single chip

white

SmartLED®

0,3mm

Chipled0,8mm SmartLED®

0,6mm

MicroSIDELED®

1,0mm Firefly®

0,5mm

MicroSIDELED®

0,6mm

Increasing drive current / output

Improved thermal performance


787mW

Electrical and Optical Power FlowCurrent Status and Optimization limit

1134mW

El. loss IQE 80% LEC 86%

Heat: 148mW

986mW

199mW 110mW

R&D status

0.35A; 3.2V

R&D status:

Popt =677mW; 60%

chip out

Pheat=457mW; 40%

677mW Popt.: 643mW blue at 350mA

Limit for 1mm chip at about 180-190lm at 350mA

Chip optimization limit:

Heat: 75mW 47mW 45mW

898mW1020mW

El. loss IQE 95% LEC 95%945mW

0.35A; 2.9V

853mW Popt =853mW; 84%

chip out

Pheat=167mW; 16%

Chip limit / Dragon:

≈ 190lm white

Popt.: 810mW blue at 350mA

155lm white

11


Phosphor concentration

Chip wavelength

Color coordinate

+

400 500 600 700nm

White Light by Phosphor Conversion

Blue emittingLED

Yellowphosphor


CIE (x,y)-Chromaticity-Diagram

460

480

500

640

620

600

580

560

540

520

683 lm/W

380

780

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

x

y

Blue Pumped Phosphors

Garnet(yellow, green)

blue InGaN-LED

Nitrides(orange, red)

Oxynitrides(yellow, green)

Orthosilicates(green, orange)

• High quality whitelight requires morethan one phosphor

• Each phosphorsystem has specificstrong and weakproperties

• Intensive researchand developmentactivities

12


spectral emission

spectral absorption

λdom

FWHMCx, cy

λRmin

Rλex

phosphor efficiencyQELE

grain characteristicsd50 (d10, d90)shape

phosphor stability

TQ T-stabilityhν-stabilitychemical stability

The Phosphor System is the Key Parameter…

phosphor property parameter relevant LED property

LED colorLED efficiencyLED color rendering/ color gamutLED stability & maintenanceLED producibility


400 500 600 700

wavelength (nm)

inte

nsity

(a.u

.)

400 500 600 700

wavelength (nm)

inte

nsity

(a.u

.)

Efficacy and Color Rendering of PC-LEDsSimulations for Various Down Conversion Approaches

400 500 600 700

wavelength (nm)

inte

nsity

(a.u

.)

CRI and Efficiency strongly depend on chosen phosphor solutionEstimation of max. 150 lm/W @ CRI 80 and 180 lm/W @ CRI 60

red & green phosphor 85 %89

CRI Efficiency

Daylight 100

standard phosphor 79 100 %

narrow yellow phosphor 59 119 %

Cx & Cy = 0,33

constant opt. Power of blue chip

13


Color Rendering and Color Preferences of White LEDs

Many options to tune color impression:

Enhancement of color saturation for more vividness by spiky spectrum

Smoothening of color contrasts for more “natural” appearance

LED light sources show often higher people preference ratings than suggested by their CRI

CRI likely not the most suitable metrics…


White LEDsColor Quality is Key for Success in General Lighting

Dynamic Daylight Simulation

Our biological clock has a strong influence on• nocturnal sleep quality• body core temperature and heart rate• mood and well being• alertness, cognition and reaction time• performance and vigilance

14


LEDs Can Play their Benefits Everywhere!USPs per Field of Application

• Design freedom• Infinite color change

possibilities

Hospitality

• Safety feeling (homogeneity, no glare)

• Energy saving• Instant on, dimming

Street, Tunnel, Parking

• Light quality and comfort• Energy saving• Additional features

Light@home

• Energy saving• Direct and indirect light• Variable scene settings

Office lighting

• Light quality• Changeable light (colour)• Energy saving (freezers)

Shop lighting

Architainment

• Design freedom• Infinite color change

possibilities

Energy Savings and TCO is important, but……there is as well emotion, amazing new designs & smart features


Street- & Tunnel-Lighting

Yantzi River Tunnel

15


Conventional system LED System

LED = Light where it should be!LEDs need less lumens to reach the brightness target: lower energy consumption and environmental protection by better directionability

• 30% of light is wasted• Light pollution disturbing residents• Birds and animals breeding can be disrupted

with unwanted light

Lamp 1

Lamp 2

• perfect use of the lumen packages• Homogeneous light distribution increased

safety, less fatigue for drivers• Animals and birds can live undisturbed

Light where it should NOT be

Light where it should be


The Optical Concepts for Technical Street Lighting

PCBLED

Oval lens

1 Oval Optics

2 Tilted focusing optics

3 Combination of wide beam spread optics and reflector

PCB

LED with focusing lenses

PCBLED

Lens with wide beam spread

Reflector OSRAM STREETlight

Advanced

OSRAM Golden DRAGON oval Plus

OSRAM Golden DRAGON Plus

(exclusive secondary optics)

4 CombinationsPCB

LED with lens ReflectorOSRAM

STREETlightProtect (HPML)

16


LED Module STREETlight Advanced

Special benefits

– Efficient and most uniform illumination of street & pavement with the reflector concept

– Illumination of street according to street lighting standard EN 13201 (glare limitation fulfilled)

– Fast and tool less module swap for easy maintenance

– Small & constant (standardized) module size enables individual luminaire designs

– Long module life time: up to 50 k hoursLED module STREETlight Advanced

•Technical illumination of service and trunk roads, in future main roads, as well as illumination of paths andplaces

Preliminary


Product Highlights / Benefits

STREETlight Protect Benefits / USP

- No light wastage with oval light distribution focusing light on targeted areas

- Modular concept, stackable,easily configurable

- Uniform heat dissipation(Long life maintenance)

- IP66 rated

- wide operating temperature -25 to 55oC enables wide range of applications

- rotational bracket (optional)

A high power modular light source which can be stacked and configured to meet all types of applications; street lighting, warehouse, freezer, factory, task lighting, etc..

17


Modular concept advantageOne standard module for all different pole heights

70 lm/W, 3.2V@ 350mA/LED = 1100 lm

8-module lamp

4-module lamp

Flexible Array – scalable to meet different street height application


HPML Module in Korea

18


Standardization in Solid State LightingEfforts are Going on all over the Globe

The innovative LED technology is on the way to revolutionize General Illumination.

SSL is leaving its niche to broaden manifold applications in various market segments.

Standardization, driven by Governments and Lighting Industries, is essential to pave the road to a successful market entry.

The key drivers are:- Energy Efficiency - Lifetime - Labeling- Environment Protection - Safety - Retrofits

Worldwide consistent standards will be the success factor for midterm push in SSL.


The Key Issues to Make LEDs Ready for Prime Time

Play the unique technology advantagesColor & dynamic lightSmall sizeUnique formsLight patterns and intensity distributions

Make SSL easy to control

Provide high quality white light at highest efficiency

Control cost - cut back the payback times go for high maintenance & high energy cost applicationsSecure the investment by getting the “-abilities” in place:

upgrade-abilityreorder-abilitycompatibility

Focus on excellent system reliability

19


The Next Wave in SSL…The Organic LED© OSRAM OS: released on Oct 20th 2009


OLED – The Aesthetics of Light

OLED positioning will be centered on the emotional perception:

√ OLED – is just light - not loaded with lot’s of luminaire materials

√ OLED – is ultimately reduced & pure aesthetics

√ OLED – delivers harmony of form and light

20


Some application examples (I)

Source: PPML design contest 2009, Osram OS

Decorative &Mood lighting


Some application examples (II)

Source: PPML design contest 2009

21


Some application examples (III)

Room SeparatorDesktop Illumination

Source: Osram OS


Outstanding Features• High energy efficiency:

- 62 lm/W on R&D level- >100 lm/W in future

• High quality white light: CRI > 80

• Diffuse non glaring area light source

• Instant on/off

• Mercury-free

• Low voltage DC driven

• Functionality- Various colors- Different color temperatures

• Design & aesthetics- Thin, flat, lightweight- Diffuse – transparent – mirror- Flexibility

Mercury free

0

0.2

0.4

0.6

0.8

1.0

1.2

380 480 580 680 780Wavelength (nm)

Nor

mal

ized

Rad

ianc

e (a

. u.)

White broad band emission

22


Transparent OLEDs open up completely new opportunities regarding design and applications!

Technology facts:

• 210cm2 active lighting area• 55% transparency• Highly conductive electrodes• No busbars required• 2 contact pads (lighting conform)

R&D Result: Large Area Transparent OLED

145 mm


OLED market will develop from high end to high volume applications

OLED Lighting - Market Development

III. General Lighting "White Volume Flatlight"

"A key segment in the world's volume lighting portfolio"

Volume Business

II. Functional Designs "Design & Illumination"

"Great value propositions by (e.g.) transparency"

Transition to Volume

I. Luxury Designs "Light Art"

"The birth of a light revolution" Extreme thin - superior CRI

Emotional factors overweigh the price

Amazing features will enable impressive, new applications.

Volume fit per cost, performance & capacity.

Market Entry

23


The Application Categories Lead to Challenging Requirements…

Luminous Objects General Illumination...to be fulfilled without sacrificing the aesthetic appeal and the lightingessentials: lumen maintenance, sustainability, low cost and efficiency

Note: Automotive applications are currently not in focus due to high required temperatures

General Illumination

- Task light- Integrated ceiling & wall light

Requirements:- High luminance level (up to

4000 Cd/m2) & directional beamshaping

Object Illumination

- Windows- Shop- Specialty

Requirements:- Large area &

transparency and/or aesthetic tiling concepts

Mood Lighting

- Decorative light- Accent light

Requirements:- Diffuse emission at

moderate luminance level (<500 Cd/m2)

- Excellent off-state appearance


OLED Beyond Glass Substrates

• First proof of principle on bendable substrates successful (top emitter on metal substrate).

• Flexible OLEDs on e.g. plastic foils will be available in 3-5 years.

• At OSRAM OS bendable and flexible substrates are part of the activities regarding R&D as well as potential applications.

24


Thank You For Your Attention

Documents

Light Emitting Diodes for Solid State Lighting