ENERGY SAVING PHOSPHORESCENT OLED LUMINAIRES DE-EE0004534

M. S. Weaver, P. Levermore, V. Adamovich, R. Ma, M. Hack and J. J. Brown Universal Display Corporation

M. Lu Acuity Brands Lighting

2012 DOE SOLID-STATE LIGHTING R&D WORKSHOP, ATLANTA 1

ation

2 Multiple High Growth Markets for OLEDs

Today 2012+

Display

Smart Phones / Tablet TV

Lower power consumption

Superior display aesthetics

Thinner form factor

Cost advantages at scale

Thinner form factor

Better display contrast

Wider viewing angle

Perfect for 3D TV

2012 / 2013+

Lighting

PHOLEDs are more energy efficient

Diffuse, pleasing light source

Thinner form factor

Environmentally friendly Lower power

consumption

Less heat gener

3 Why the excitement About OLED Lighting

• Energy efficient – environmentally friendly • Ultra-low operating temperatures • Low drive voltage • Long lifetime

• Highly desirable color quality • Wide range of CCT, CRI possible • Color tunable • Instant “ON” , Dimmable without flicker • No glare, no noise

• Novel form factor • Thin and lightweight • Transparent • Non-breakable, Flexible, Rollable…..

Acuity Brands RevelTM, -- five panel luminaire

4 Program goals

Technical goals • Fabricate all phosphorescent OLED luminaire

using 15 cm x 15 cm panels • High efficacy (>70 lm/W) • Color tunable between 2,700K and 4,000K • CIE meets Energy Star Criteria for SSL • CRI >85 • LT70 >25,000 h at Lo=2,700 cd/m2 (6,000 lm/m2)

Commercial goal: • Develop prototype luminaires ready for

commercialization

5 OLED Performance Design Rules

OLED Power Efficacy LER x IQE x EEF x OC LER = Luminous Efficacy of Radiation ( = Max efficacy of emission spectra) IQE = Internal Quantum Efficiency EEF = Electrical Efficiency ( = Optical Energy Gap – Applied Voltage) OC = Outcoupling Efficiency

OLED Lifetime

Higher Efficacy

Lower Temperature

Longer Lifetime

Phosphorescence Is Core to Energy Efficient OLEDs 6

Phosphorescent OLEDs* - PHOLEDs

• Radiation is from triplet excitons, i.e., 4 of 4 spin states or ~100% IQE

• Fluorescent OLEDs emit through singlets, limiting the IQE

• Impact of PHOLEDs: Minimizes required drive current to achieve High power efficacy Less heat generation Longer lifetime

* M.A. Baldo, et. al., Nature., 1998

7 General Designs for White OLEDs

WOLED SOLED STRIPES

White OLED Stacked (or Tandem) Color Tunable 1-3 emitters

Pixel Efficacy: UDC Status & Targets

Pixel Efficacy = LER x IQE x OC x EEF

LER = Luminous Efficacy of Radiation ( = Max efficacy of emission spectra) IQE = Internal Quantum Efficiency OC = Outcoupling Efficiency EEF = Electrical Efficiency Factor ( = Optical Energy Gap – Applied Voltage)

UDC Status UDC Target and Practical Limit LER [lm/W] 327 350 IQE [%] ~85% 95% OC [%] ~40% 60% EEF [%] ~70% 90% Pixel Efficacy [lm/W] 80 (at 1,000 cd/m2) 180 (at 3,000 cd/m2)

White PHOLEDs already emit with IQE 100% at low luminance. Challenge is to maintain IQE 95% at 3,000 cd/m2.

UDC White OLED Pixel Efficacy Target = 180 lm/W

9 New White PHOLED Material System – 85 lm/W

Pixel 2 mm2

Without Outcoupling

With Outcoupling

Efficacy [lm/W] 40 85

CRI [Ra] 85 -

Luminance [cd/m2] 1,000 1,000

EQE [%] 23 46

Voltage [V] 3.8 3.6

Duv 0.004 -

CCT [K] 2,740 -

Efficacy Enhancement 1.00 2.12x

LT70 [hrs] 12,000 35,000

EL In

tens

ity [W

/sr/m

2 ]

0.12

0.10

0.08

0.06

0.04

0.02

0.00 400 450 500 550 600 650 700 750

Wavelength [nm]

*Acceleration Factor AF = 1.477 *Outcoupling data measured with 50 mm x 50 mm x 12 mm block *Chromaticity measured at 10 mA/cm2.

10 White PHOLEDs in UDC Pilot Line

2004 2006 2008 2010 2012 2014 2016 2018 2020 0

20

40

60

80

100

120

140

160

180 UDC Pixel Efficacy (2 mm2) UDC Panel Efficacy (15 cm x 15 cm) U.S. DOE Panel Performance Projection (15 cm x 15 cm)

Pow

er E

ffic

acy

[lm/W

]

Incandescent bulbs (10 - 12 lm/W, 1 khr)

Fluorescent tubes (40 - 70 lm/W, 25 khrs)

86 lm/W, 25 khrs at 6k lm/m2

125 lm/W, 50 khrs at 10k lm/m2

168 lm/W, 100 khrs at 10k lm/m2

3,000 cd/m2 ≈ 10,000 lm/m2

LED Lamps (60 - 80 lm/W, 50 khrs)

11 General Designs for White OLEDs

WOLED SOLED STRIPES

White OLED Stacked (or Tandem) Color Tunable 1-3 emitters

12

5

30

Example Red PHOLED performance

LE [cd/A] PE [lm/W]

1000 2000 3000 4000 5000

140

Lum

inou

s Ef

ficie

ncy

[Cd/

A]

25

Pow

er E

ffica

cy [l

m/W

]

EL n

orm

aliz

ed [a

.u.]

0.8

0.6

0.4

0.2

30 20

15 20

10

10

0 0 0 400 450 500 550 600 650 700

Wavelength [nm] Luminance [cd/m2]

1931 CIE

x y λ max [nm]

FWHM [nm]

0.66 0.34 620 56

Luminance [cd/m2]

Voltage [V]

LE [cd/A]

EQE [%]

PE [lm/W]

LT70% [h]

1,000 2.9 29.0 24.5 31.4 270,000

2,900 3.3 27.4 23.1 25.7 30,000

Data reported without any added outcoupling enhancement

13 Example Green PHOLED performance

90112080

LE [cd/A] PE [lm/W]

1000 2000 3000 4000 5000

Luminance [cd/m2]

0.2

0.4

0.6

EL n

orm

aliz

ed [a

.u.]

Lum

inou

s Ef

ficie

ncy

[Cd/

A]

70

60

50

40

30

0.8100

Pow

er E

ffica

cy [l

m/W

]

80

60

40

20 20 010 400 450 500 550 600 650 700

Wavelength [nm] 0 0

1931 CIE

x y λ max [nm]

FWHM [nm]

0.41 0.58 544 66

Luminance [cd/m2]

Voltage [V]

LE [cd/A]

EQE [%]

PE [lm/W]

LT70% [h]

1,000 2.8 85.6 23.4 97.5 600,000 2,800 3.0 83.1 22.7 87.0 100,000

Data reported without any added outcoupling enhancement

14 Example Blue BD412 PHOLED performance

60 60 155

50 50

LE [cd/A] PE [lm/W]

1000 2000 3000 4000 5000

0.2

0.4

0.6

EL n

orm

aliz

ed [a

.u.]

400 450 500 550 600 650 700

Lum

inou

s Ef

ficac

y [c

d/A]

0.845 40 40

Pow

er E

ffica

cy [l

m/W

]

35

30 30 25 20 20 15

10 10

5 00 0

Wavelength [nm] Luminance [cd/m2]

1931 CIE

x y λ max [nm]

FWHM [nm]

0.18 0.40 476 56

Luminance [cd/m2]

Voltage [V]

LE [cd/A]

EQE [%]

PE [lm/W]

LT70% [h]

1,000 5.6 50.4 22.0 28.1 9,000

550 5.1 52.2 22.7 31.9 27,000

Data reported without any added outcoupling enhancement

15 RGB performance status and program goals

Color 1931 CIE (x, y) Luminance [cd/m2]

Efficacy [lm/W] Lifetime LT70 [h]

Target Status Target Status

Red 0.64 ≤ x ≤ 0.68 0.30 ≤ y ≤ 0.35 2,900 > 25 26 > 25,000 32,000

Green 0.30 ≤ x ≤ 0.50 0.40 ≤ y ≤ 0.65 2,750 > 80 87 > 25,000 100,000

Blue 0.15 ≤ x ≤ 0.20 0.30 ≤ y ≤ 0.40 550 > 30 32 > 25,000 27,000

Data in table reported without any added outcoupling enhancement

Panel Design

All layers & Cathode Contacts

Preliminary individual stripe performance in panel

EL

Inte

nsity

[W/s

r/m2 ]

0.06

0.05

0.04

0.03

0.02

0.01

0.00

Blue Green Red

400 450 500 550 600 650 700 750

Wavelength [nm]

B stripe G stripe R stripe 1000cd/m2

(0.171, 0.390) 53 cd/A 4.4 V

38 lm/W

1000 cd/m2

(0.412, 0.575) 63 cd/A 2.7 V

74 lm/W

1000 cd/m2

(0.622, 0.374) 30 cd/A 3.0 V

31 lm/W

Data reported without any added outcoupling enhancement

Preliminary 15 cm x 15 cm Panel Performance

400 450 500 550 600 650 700 750 0.0000

0.0002

0.0004

0.0006

0.0008

0.0010 E

L In

tens

ity [W

/sr/m

2 ] 2780 K 3350 K

Wavelength [nm]

Luminance [cd/m2]

Light Output [lm]

CIE 1931 (x, y) CRI CCT

[K] Duv Efficacy [lm/W]

1000 35 (0.462, 0.426) 90 2,800 0.005 54

1000 34 (0.421, 0.413) 81 3,400 0.006 54

*Emissive Area = 115 cm2

*All data includes light extraction enhancement achieved using a 12 mm thickness light extraction system

Example panel spectra and panel color gamut

• Color tunable between 2500K to 4000K

Initial prototype striped panel images

Stripes panel

Stripes panel + diffuser over half of panel

Stripes panel + diffuser

 

Luminaire Design #1 Features

Design #1 sculpts a ceiling with brightness and texture. Each luminaire creates a lattice design that will seamlessly integrate in a variety of architectural settings. Designed to mount in a 2’ x 4’ ceiling grid. Also compatible with 2’ x 2’ ceiling grids.

Candlepower Distribution

• 30 OLED panels • 3645 lumens • 1214 cd @ 0° • 58 Watts • 63 lpw

 

Luminaire Design #2 Features

Design #2 is an elegant arc of OLED illumination that gestures downward to the occupant, giving the sense of an illuminated canopy of light. Mounts to ceiling surface with a single mounting point, simplifying installation. Compatible with grid ceiling applications.

Candlepower Distribution

• 32 OLED panels • 4320 lumens • 1439 cd @ 0° • 62 Watts • 70 lpw

Typical Applications

Office Retail

Summary & Future Work

Program proceeding well to fabricate color tunable PHOLED luminaires

- Pixel performance exceeds program goals - First color tunable (2500K – 4000K) panels fabricated - Current panel efficacy = 54 lm/W at 1,000 cd/m2

- Further panel optimization in progress - Luminaire designs completed - On target to deliver color tunable luminaires in 2012 that meet the

program specs

26 Acknowledgements

ENTIRE UDC TEAM

SUPPORT IN PART FROM US DEPARTMENT OF ENERGY (IN ADDITION TO DE-EE0004534)

DE-SC0002122, DE-EE0006266, DE-EE0003253, DE-SC0004281, DE-SC0004282, DE, FG02-08ER85082

Thank you!