OLEDs, PLEDs, QLEDs Perovoleds and RELEDs

Professor Poopathy Kathirgamanathan (P. K. Nathan) Regional Vice President, Europe - Society for Information Displays

p.kathir@brunel.ac.uk

OLED Emitters Quantum Dots

Topics

1.Background2.OLEDs3.Quantum Dots for Rec 20204.High Triplet Energy Hole Transporters and Electron

Transporters

http://youtu.be/D0WV1R9RfI0

http://youtu.be/Ws76e-AAApI

http://youtu.be/SKIsnei0k4A

http://youtu.be/p4aDAkC61Wk

http://youtu.be/RgoMnroRnhc

http://youtu.be/HGHg-f74NAA

http://youtu.be/UWKoJjViOUg

http://youtu.be/QC-nUMkMOFc

Our Recent Work

ITO or Silicon

Hole Injector (Buffer)

Hole Transporter

Host + Dopant

Electron Transporter

Electron Injector

Aluminium

Contrast Enhancing Material

Glass

Over the last 10 years, we made over 2500+ ETL, 400+ EIL,

100+ Li Complexes, 600+ emitters, 100+ hole transporters and

9000 OLED test panels (100 mm x 100 mm).

HBLEBL

ITO-4.7eV

LiF/Al-3.1eV

Mg:Ag-3.6eV

HIL HTL

LUMO

HOMO

EILETL

Al-4.1eV

IDtechEX

0

2,000

4,000

6,000

8,000

10,000

12,000

2010 2011 2012 2013 2014 2015 2016 2017 2018

Year

Re

ven

ue

US$

/ m

illi

on

EIL

ETL

Emitter

Host

HTL

HIL

Market: Oled Materials

0

1,000

2,000

3,000

4,000

5,000

6,000

2010 2011 2012 2013 2014 2015 2016 2017 2018

Year

Re

ven

ue

US$

/ m

illi

on

EIL

ETL

HTL

HIL

Current Market

ALUMINIUM

ELECTRON INJECTOR*

CONTRAST ENHANCING MATERIAL

ELECTRON TRANSPORTER*

HOST & DOPANT

HOLE TRANSPORTER*

HOLE INJECTOR (BUFFER)

ITO / SILICON

GLASS / PLASTIC

Year

1940 1950 1960 1970 1980 1990 2000 2010

log

(

el

/ lm

W-1

)

-4

-3

-2

-1

0

1

2

Col 13 vs Col 14

Col 15 vs Col 16

Col 17 vs Col 18

Col 19 vs Col 20

A B

CD

EF

G

H

J

IUDC, OLED-T

Organic Electroluminescence

A: A. Barnose

e

et al. B: M. Pope et al. C: Helfrich et al. D: J. Dresner et al. E: R. Partridge et al. F: P. S. Vincentt et al. G: C. W. Tang et al. H: C. Hosokawa et al. I: P. Kathirgamanathan et al. J: J. H. Burrough et al.

K: Princeton Univ., UDC,

Novaled and

Kathirgamanathan et al..

K

Incandescent Lamps

Fluorescent Lamps

Fluorescents

Polymers

PLED Configuration Small Molecules OLED Configuration

5.3 eV

4.8 eV

ITO

3.6 eV

2.4 eV

5.4 eV

3.1 eV

5.7 eV

LiF/Al

Al

CuPc-NPB

Alq3

4.8 eV

ITO

MgAg

HM

TP

D (

HT

L)

60 n

m

Alq

3 (E

TL

)

50 n

m

NT

AZ

(E

ML

)

25 n

m

3.7 eV

5.6 eV

2.3 eV

2.7 eV

6.6 eV

5.6 eV

3.0 eV

6.0 eV

3.3 eV

Ir(p

py) 2

(aca

c)

6.7 eV

3.2 eV

BC

P (

HB

)

10 n

m

NN

N

NTAZ

N

Ir

O

O

CH3

CH3

2

Ir(ppy)2(acac)

1988

Doped HTL and ETL

4.8 eV

ITO

LiF/Al

HT

L +

Acc

epto

r

ET

L

Host

+ D

opan

t

HT

L

ET

L +

Donor

3.1 eV

+

NC

NC

CN

CN

F

FF

F

E.g. Bathophen + Li

N

N

NN

CH3

H3C

CH3

E.g. m-MTDATA + TF-TCNQ

NN

To reduce operating voltage(1000 cd m-2 @ 3 V)

To enhance efficiency (over 100 cd A-1) Ref:

P Kathirgamanathan et al., Mat. Lett., 6, 40 (1999)

www.novaled.com

IL = Hole transporting polymer

LCD’s vs. OLED’sThe Complexity of LCD’s vs. The Simplicity of OLED’s

Pioneer’s first OLED Display (Car Radio)

CRT

LCD

OLED TV

1930-2000 1970-? 2010-?

IMID 2015

IMID 2015

QD/LEDPure OLED

LG £1850 (5 year guarantee) Samsung £2400

Konica Minolta’s OLED Lit Signage.

Konica Minolta, 15, 000 flexible OLEDs, TULIP Festival

Spectral Output

J.-H. Jou et al., Advanced Functional Materials, 23(21), pages 2750–7, June 6, 2013

P arameter Inc andes c ent C F L Inorg anic L E D OL E D

E fficiency/

lm W -1

8-15 50-80 30-100 40-100

C R I 100 70-80 40-85 85-90

L ifetime/hours 800 10000-20000 15000-60000 20000

C ost/£ 0.50 3 1-5 100

(300mm X 300mm)

C onsumption

C ost

High L ow L ow L ow

E nvironmental

Impact

B AD B AD

Hg, UV, P oor C R I

P oint

S ource

G ood

P lanar/ Diffuse

P arameter Inc andes c ent C F L Inorg anic L E D OL E D

E fficiency/

lm W -1

8-15 50-80 30-100 40-100

C R I 100 70-80 40-85 85-90

L ifetime/hours 800 10000-20000 15000-60000 20000

C ost/£ 0.50 3 1-5 100

(300mm X 300mm)

C onsumption

C ost

High L ow L ow L ow

E nvironmental

Impact

B AD B AD

Hg, UV, P oor C R I

P oint

S ource

G ood

P lanar/ DiffuseBad Bad

P arameter Inc andes c ent C F L Inorg anic L E D OL E D

E fficiency/

lm W -1

8-15 50-80 30-100 40-100

C R I 100 70-80 40-85 85-90

L ifetime/hours 800 10000-20000 15000-60000 20000

C ost/£ 0.50 3 1-5 100

(300mm X 300mm)

C onsumption

C ost

High L ow L ow L ow

E nvironmental

Impact

B AD B AD

Hg, UV, P oor C R I

P oint

S ource

G ood

P lanar/ Diffuse

P arameter Inc andes c ent C F L Inorg anic L E D OL E D

E fficiency/

lm W -1

8-15 50-80 30-100 40-100

C R I 100 70-80 40-85 85-90

L ifetime/hours 800 10000-20000 15000-60000 20000

C ost/£ 0.50 3 1-5 100

(300mm X 300mm)

C onsumption

C ost

High L ow L ow L ow

E nvironmental

Impact

B AD B AD

Hg, UV, P oor C R I

P oint

S ource

G ood

P lanar/ Diffuse

Efficiency : LED’s vs. OLEDs

2000 2005 2010 2015 2020

Lum

inou

s E

ffica

cy (l

m/W

)

0

20

40

60

80

100

120

140

160

180

200

Small White LED High Power Cool White LED

High Power Warm White LED

Incandescent

CFL

Tube FL

HID

LED

OLED

N

O

N

O

Al

ON

Tb

O

O

CH3H3C

H3C

H3C

H3C CH3

_

3

O P N P

n

S S S S S S

(a) Perylene (b) Metal chelate (c) Rare earth chelate (e) Polymer (e) Sexithiophene

Few mm2 discrete

element device

Conjugated

Polymers

e.g. PPV

Inorganic EL Materials

(only AC operation) Organic EL Materials

(AC or DC operation)

Molecular

Solids

Fluorescent

Dyes

e.g. Perylene

Metal

Complexes

e.g. Alq3 , Ir(III)L3

Flat panel display

Group II/VI

Compounds

e.g. ZnS:dopants

Group III/V

Compounds

e.g. GaAs, GaN

EL Materials

Rare Earth

Chelates

e.g. Tb(III)

Oligomers

e.g. Sexithiophene

N

N

N

IrN

F

F

CN

2

N

Ir

3

Small Molecules Polymer Oligomers

CdSe/

ZnS

QD

TADF

Perovskites

50300200100

Lmax/ cd m-2

80,000

30

50

60,000

40,000

20,000

10000

1

10

100

10,000

1000

100000

10000

1000

100

10

PL Stability/ 60° C,

85% RH air5000 hr

400C

Tg/Tm

PL100%

Mobility/ 10-7 cm2 V-1 s-1

Response Time /ms

Device Life Time

continuous DC/ hr

EL/lm W-1

100000

100EL/ cd A-1

Target

Target

Target

Target

Efficiency

10

20

40

Target

Target

Complete conversion of singlets to triplets

Potential for 100% internal efficiency in OLEDs

Fluorescent vs. Phosphorescent Emitters

N

Ir

3

S

N

O ON

C545T

Phosphorescent Red (30g)

25 cd/A at 1000 cdm-2

Solution Processable

NNO

O

Ph

Ir

N

2

Phosphorescent Green (20 g)

50 cd/A at 1000 cdm-2

N

N

N

IrN

F

F

CN

2

22 cd/A at 1000 cdm-2

Phosphorescent Blue

Purity Level: 99.98%

Green Phosphorescent Materials

Ref: P. Kathirgamanathan, R.Price, S.Ganeshamurugan, G.Paramaswara, M.Kumaraverl, A.Partheepan, S.Selvaranjan,J.Antipan-Lara and S. Surendrakumar., Patent No: WO 2005/080526; Priority date: 14 February 2004

NNO

O

Ph

Ir

N

2

NNO

O

Ph

Ir

N

2

NNO

O

Ph

Ir

N

CF3 2

NN

Ir

N

N

N

CN

F

F

2

N

N

N

IrN

F

F

F

CN

2

max 502nm (DCM)

max 528nm (DCM)

max 509nm (DCM)

max 526nm (DCM)

max 520nm (DCM)

Blue Phosphorescent Materials

N

N

N

IrN

F

F

2

N

N

N

IrN

F

F

2

N

N

N

IrN

F

F

CN

2

N

N

N

IrN

F

F

2

N

N

N

IrN

F

F

CN

2

N

N

N

IrN

F

2

NNO

O

Ph

Ir

N

F

F

2

NNO

O

Ir

N

F

F

F

2

NNO

O

Ir

N

F

F

NC

2

NNO

O

Ph

Ir

N

F

2

NN

NNO

O

Ph

Ir

2

NN

Ir

N

N

N

2

N

N

N

Ir

N

2

Ref: P. Kathirgamanathan, R.Price, S.Ganeshamurugan, G.Paramaswara, M.Kumaraverl, A.Partheepan, S.Selvaranjan,

J.Antipan-Lara and S. Surendrakumar., Patent No: WO 2005/080526; Priority date: 14 February 2004

max 479nm (DCM)

max 484nm (DCM)

max 480nm (DCM)

max 495nm (DCM)

max 477nm (DCM)

max 470nm (DCM) max 468nm (DCM) max 462nm (DCM)

max 493nm (DCM) max 485nm (DCM) max 485nm (DCM)

max 469,493nm (DCM)

max 483nm (DCM)

Ground stateSinglet

Radiativeabsorption

Excitedsinglet

Excitedtriplet

ligandfluorescence

ligandphosphorescence

Radiativeemission(fluorescence)

Non-radiativeemission

Lanthanide oractinide excitedstates

Trappedstates

LanthanideFluorescence

Excitation and Emission Mechanism: Rare Earths

PL and EL Spectra of Tb(III), Dy(III), Eu(III) & Sm(III)

Wavelength / nm

350 400 450 500 550 600 650 700 750

Inte

nsity

/ arb

. uni

t

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

E101+Blue Dopant-1 [(x, y) = 0.209, 0.297]

E101+Blue Dopant-2 [(x, y) = 0.176, 0.241]

E246+Green Dopant [(x, y) = 0.291, 0.674]

E246+Red Dopant [(x, y) = 0.631, 0.368]

E101 [(x, y) = 0.178, 0.366]

Super Blue [(x,y) = 0.150,0.290]

Hyper Blue [(x,y) = 0.175,0.177]

E122 [(x, y) = 0.154, 0.063]

Electroluminescent Spectra of Selected Fluorescent Red, Green and Blue Materials

Electroluminescent Spectra of Selected Phosphorescent Materials (Super Colours)

Wavelength / nm

400 450 500 550 600 650 700 750

Inte

nsity

/ ar

b.un

it

0.00

0.02

0.04

0.06

0.08

0.10

0.12Super-Blue (E165-CN)(x, y) = 0.14, 0.26

Super-Green (E255a)(x, y) = 0.33, 0.62

Super-Red (E355a)(x, y) = 0.67, 0.33

Electroluminescent Spectra of Selected Rare Earth Chelates

Wavelength / nm

350 400 450 500 550 600 650 700 750

Inte

ns

ity /

arb

. u

nit

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

E201 [(x, y) = 0.307, 0.615]

E301 [(x, y) = 0.668, 0.329]

O

O

Tb

_

N

N

O P N PO

O

Tb

_

Tb(TMHD)3.Phen Tb(TMHD)3.OPNP

3 3

Uoyama, Goushi, Shizu, Noumura and Adachi, Kyushu University,Nature, 492 (2012)234

Conventional vs. Thermally Activated Delayed Fluorescence

Metal free !

Conventional vs. Thermally Activated Delayed Fluorescence

Cu N

N CF3

F3C

Cu

N N

CF3F

3C

NN

CF3

CF3

Cu

Samsung’s Patent

Red Emitter,

Current Efficiency, 1 cd/A

Analogous Ag complex was also reported.

N

NN

N Pt

Cl

ext = 11.6 %

I = 39 cd A-1

p = 27.2 lm W-1

X,y = (0.19, 0.32)

N

Au

N

ext = 12.8 %

I = 36 cd A-1

p = 26 lm W-1

x,y = (0.29, 0.37)

P

P

Cu(I)

Br

_

M. Hashimoto, et al., JACS. Commun, 2011, 133, 10348-10351

5 cd m-2

50 lm W-1

63 cd A-1

ext 21.3 %

HK University

/nm

400 500 600 700 800

Nor

mal

ised

Inte

nsity

0.0

0.2

0.4

0.6

0.8

1.0

1.2

DCJTi

Eu(III)

E355a- Ir

Q-D Red N

S

Ir

Ir

NN

O

O

CH3

2

_

OH3C

CH3

NC CN

N

H3C

H3C

H3C CH3

O

O

Eu

_N

N

3

O

O

Eu

_

3

O P N P

_N

N

3

S

F3C

O

O

Eu

Eu(DBM)3.PhenEu(DBM)3. OPNP

Eu(TTA)3. Phen

DCJTI

E355A

QD-Red

Colour NTSC Rec 2020

Red (0.670, 0.33) (0.708, 0.292)

Green (0.210, 0.710) (0.170, 0.797)

Blue (0.140, 0.080) (0.131, 0.046)

White (0.310, 0.316) (0.3127, 0.3290)

REC 2020

NTSCREC 2020

Red Qoleds Based on CdSe/ZnS

100 mm x 100 mm

Performance Data.All data at 1000 cdm-2.

Colour Fluorescents

(v)

Phosphorescents

(v)

Polymers/Dendrimers

(s)

Quantum Dots

(s)

Red (0.65, 0.35),

300-500 kh,

10 cd/A

(0.64, 0.36),

330 kh,

30 cd/A, 22 lm/W

(0.63, 0.37),

350 kh,

30 cd/A

Red (0.69, 0.31),

250 kh,

17 cd/A, 10 lm/W

(0.67, 0.32)

200 kh,

11 cd/A

(0.69, 0.31),

2 kh,

15-20 cd/A,

15 lm/W

Green (0.29, 0.61),

65 kh,

31 cd/A

(0.34, 0.62),

400 kh,

78 cd/A

50 lm/W

(0.30, 0.63),

140 kh,

50 cd/A

(0.17, 0.73)

2 kh

70 cd/A

50 lm/W

Blue (0.15, 0.14),

50 kh,

10 cd/A,

5 lm/W

(0.18,0.40),

20 kh

50 cd/A

30lm/W

(0.15, 0.14),

21 kh

6 cd/A

(0.16, 0.05)

0.01 kh,

0.55 cd/A

0.26 lm/W

Displays Development

Solciet (ULVAC)

Solciet – £1 million (100 mm x 100 mm), Tact Time: 1-2 hours

Satella- Cluster tool , £3 million(200mm x 200 mm), Tact Time: 30 minutes

Zelda – Mass Production, £20 million (400 mm x 500 mm), Tact Time: 4 minutes

ULVAC (OLED) Prototyping Equipment in A1000 Clean Room,

Brunel

300 g per 8 hour day

World Class Processing Expertise

FLEXOLIGHTINGLong Life, Large Area, Large (High) Uniformity,

Flexible and Conformable OLEDs for Lighting

www.flexolighting.eu

25 lm/W, 40 cd/A

Light Extraction Film

Hole Injectors

Hole Transporters

Host+ R+G dopants

Host + Blue dopants

ZnO (Printed)

Cu (electroless / printed / evaporated

Steel - Cathode

-

Encapsulation +

OVPD or VTEPossible Printing

Transparent Au or Conducting Polymers & Graphene

Copper track

Microlense

Red and Green Quantum Dot Based LEDs

(QLEDs): Towards Achieving REC 2020 Color Coordinates

http://youtu.be/D0WV1R9RfI0

http://youtu.be/Ws76e-AAApI

http://youtu.be/SKIsnei0k4A

http://youtu.be/p4aDAkC61Wk

http://youtu.be/RgoMnroRnhc

http://youtu.be/HGHg-f74NAA

http://youtu.be/UWKoJjViOUg

http://youtu.be/QC-nUMkMOFc

Our Recent Work

CdSe

ZnS

Quantum Dots

Conduction Band

Valence Band

HOMO

LUMO

Eg Surface

state usually

Bbocked by capping ligand

Distance

in nanometer

hv

Infinite distance

Deep

trapEg

Shallow

trap

What are quantum dots ?

• Crystalline fluorophores

• CdSe semiconductor

core

• ZnS Shell

CdSe

ZnS

Some Players – QD Vision, Nanoco, Nanosys, Samsung, Sony, Dow, Merck

𝐸 =𝑛2ℎ2

8𝑚𝐿2

CdSe

R

ZnS

6 nm

λem = 650 nm

CdSe

B

ZnS

2.5 nm

λem = 480 nm

CdSe

G

ZnS

3.5 nm

λem = 520 nmZnS

InP

4 nm

λem = 530 nm𝐸 =

𝑛2ℎ2

8𝑚𝐿2

Theoretical decomposition schematic for the preparation of TOPO capped

CdSe using a single source precursor

Se

Se R

R

MePO

P

OP

O

P O

P

O

P

Oheat

Decompositionin TOPO

Nucleationof

CdSe

heat

growth

heat

growth

EgEg

heat

growth

Energy levels as a functionof particle size

heat

growth

CdCl2+

Synthesis of CdSe Quantum Dots

Paul O’Brien, Manchester

Co-Founder, Nanoco

/nm

400 500 600 700 800

No

rma

lise

d I

nte

nsity

0.0

0.2

0.4

0.6

0.8

1.0

1.2

DCJTi

Eu(III)

E355a- Ir

Q-D Red N

S

Ir

Ir

NN

O

O

CH3

2

_

OH3C

CH3

NC CN

N

H3C

H3C

H3C CH3

O

O

Eu

_N

N

3

O

O

Eu

_

3

O P N P

_N

N

3

S

F3C

O

O

Eu

Eu(DBM)3.PhenEu(DBM)3. OPNP

Eu(TTA)3. Phen

DCJTI

E355A

QD-

Red

0

5

10

15

20

25

30

1985 1990 1995 2000 2005 2010 2015 2020

Cu

rren

t E

ffic

ien

cy /

cd

/A

Year

Red Devices

OLED (Fluorescent) - Red

OLED (Phosphorescent) -RedPLED - Red

Dendrimers - Red

Rare Earth Chelates - Red

QLED(CdSe/ZnS)

OLED (Ph)

OLED (Fl)

Dendrimers

REC

PLED

TADF

QLED (Cd Free)

0

10

20

30

40

50

60

70

80

90

1985 1990 1995 2000 2005 2010 2015 2020

Cu

rren

t E

ffic

ien

cy /

cd

/A

Year

Green Devices

OLED (Fluorescent) -GreenOLED (Phosphorescent)

PLED - Green

Dendrimers - Green

Rare Earth Chelates -GreenQLED (CdSe/ZnS) -Green

OLED (Fl)

OLED (Ph)

PLED

Dendrimers

REC

QLED(CdSe/ZnS)

QLED(Cd Free)

TADF

0

5

10

15

20

25

30

35

1985 1990 1995 2000 2005 2010 2015 2020

Cu

rren

t E

ffic

ien

cy /

cd

/A

Year

Blue Devices

OLED (Fluorescent) - Blue

OLED (Phosphorescent) -BluePLED - Blue

Dendrimers - Blue

Rare Earth Chelates - Blue

QLED (CdSe/ZnS) - Blue

OLED (Fl)

OLED (Ph)

PLED

Dendrimers

REC

QLED(CdSe/ZnS)

QLED (Cd Free)

TADF

Vacuum level

ITO

ZnO

CdSe/

CdS

QDs

NPB

HIL

Al

4.8

~ 3.8~ 2.4

5.5

5.5

9.9

4.2

B. S. Mashford et al, Nature Photonics,

7, May 2013, 407.

Red QD (CdSe/CdS): 19 cd/A, 25 lm/W

Optimum Thickness: 45 nm of QD

Life-Time: 4 hours @ 1000 cd/m2

CIE (x, y) = 0.68, 0.31)

Current Injection: SCL

N

N

N

N

N

N

CN

CN

CN

CN

NC

NC

4.8 eV

4.2 eV

2.6 eV

4.0 eV

2.5 eV2.3 eV

5.7 eV

4.3 eV

ITO

TCTA NPD

HAT-CN

AZO: Cs2CO3 Blending

7.5 eV

5.7 eV

6.1 eV

5.6 eV5.4 eV

9.5 eV

Al

e-

h

h

H-M. Kim and J. Jang, SID 2014 Digest, 67.

6.5 cd/A CIE (x,y) =(0.70, 0.30)

CdSe/CdS/ZnS

N

N

N

N

N

N

CN

CN

CN

CN

NC

NC

N

N

N

N

NN

4.8 eV

4.2 eV

2.6 eV

3.3 eV

2.5 eV2.3 eV

5.7 eV

4.3 eV

ITO

TCTA NPD

HAT-CN

AZO: Cs2CO3 Blending

7.5 eV

5.7 eV

5.6 eV

5.6 eV5.4 eV

9.5 eV

Al

e-

h

h

H-M. Kim and J. Jang, SID 2014, 67.

28 cd/A

CIE (x,y)=0.16, 0.75) CdSe/CdS/ZnS

Holloway et al, SID, 2015Green QD – 40-80 cd/A?

J. Lim et al, ACS Nano., 7, 9019 (2013)

10.9 cd/A

Mean: 8.859485 nm

Std. Dev.: 2.582179 nm

Max: 12.62415 nm

Min: 3.923416 nmNum. of Measurements: 12

CPU Time: 9.5 sec

Mean: 9.011328 nm

Std. Dev.: 2.265977 nm

Max: 14.90578 nm

Min: 5.368823 nmNum. of Measurements: 15

CPU Time: 7.4 sec

Mean: 10.33649 nm

Std. Dev.: 3.158291 nm

Max: 15.89002 nm

Min: 4.66029 nmNum. of Measurements: 13

CPU Time: 2.3 sec

Current Efficiency vs. CIE x

CIE x

0.620 0.640 0.660 0.680 0.700 0.720

I/ cd A

-1

0

10

20

30

Phos. Emitter

Brunel

Holloway

JJ

0.708

Current Efficiency vs. CIE x

CIE x

0.670 0.680 0.690 0.700 0.710 0.720

I/ cd

A-1

0

2

4

6

8

10

12

14

Brunel

Holloway

JJ

Colour NTSC Rec 2020

Red (0.670, 0.33) (0.708, 0.292)

Green (0.210, 0.710) (0.170, 0.797)

Blue (0.140, 0.080) (0.131, 0.046)

White (0.310, 0.316) (0.3127, 0.3290)

RED QD (0.695, 0.302)

Red Phosphorescent (0.660,0.330)

X

Green QDX=Green Phos.

X

(0.712, 0.288)

X

Material CIE(x,y) Current Efficiency/cd/A Life-Time at 1000 cdm-2

Phosohorescent

red

(0.64, 0.36) 24-30 200000 hours

QD (CdSe/CdS)-QD

Vision, MIT

(0.68, 0.32) 18 ?

QD

(CdSe/CdS/ZnS)

Holloway et al

(0.69. 0.30) 12 ?

QD

(CdSe/CdS/ZnS)

JJ et al

(0.70, 0.30) 6.5 ?

Brunel (0.695, 0.305) 10 1000 + hours

Brunel (0.708, 0.292) 4 250 hours

Brunel (0.712, 0.288) 0.5-1.0 On going

Conclusions:

1.Highly saturated red (0.712, 0.288) and green [Two types, (0.118, 0.665) and (0.186, 0.738)] QOLEDs have been demonstrated.

2. Life-Time in excess of 1000 hours has been obtained at 1000 cdm-2

High Triplet State and High Tg Hole Transporters:High Performance at High Luminance

Prof. J. Jang

Key Technical Requirements for Deep Blue PHOLEDs

High triplet energy HTL (ET > 2.8 eV)

• Triplet exciton blocking: No triplet exciton quenching by HTL

High triplet energy ETL (ET > 2.8 eV)

• Triplet exciton blocking: No triplet exciton quenching by ETL

High triplet energy host (ET > 2.8eV)

• Efficient energy transfer to dopant• Little back energy transfer from dopant to host

High efficiency blue dopant (ET ~ 2.7 eV)

• Deep blue emission• High quantum efficiency Prof. Jun Yeob Lee, IMID 2014

Ideal Device Design For Phosphorescent OLEDs

Triplet energy

diagram

HOMOHIL < HOMOHTL = HOMOEML

LUMO HTL < LUMO EML

HTL (ET) > EML (ET)

H

IL

HIL

HT

L

EM

L

ET

L

HOMOETL > HOMOEML

LUMOETL = LUMO EML

ETL(ET) >EML(ET)

High triplet energy host (Host(ET) > Dopant (ET))

Bipolar charge transport properties

Charge balance

H

T

L

E

M

L

ETL

HTS

series T

C

T

A

TPBi

2.6 eVT

rip

let

E2.8 eV

2.4 eV

x xo o

NPBT

C

T

A

TPBi

2.6 eV

Tri

ple

t E

2.8 eV

2.4 eVx

o o

2.3 eV

o

Ir(ppy) 2acac

Ir(ppy) 2acac

HTS Series - High triplet energy

JJ

N N

CH3 H3C

Hole Transporters

TPD

N N

-NPB

N

N

NN

CH3

H3C

CH3

m-MTDATA

Hole

Transporter

Tg

(C)

mh (cm2 V-1 s-1)

TPD 61 1 x 10-3

-NPB 98 1 x 10-4

m-MTDATA 75 2.7 10-5

Spiro-tad 133 1x 10-5

HOMO: -5.4 eV

LUMO: -2.4 eV

N

N N

N

Spiro-TAD

N N

CH3 H3C

Hole Transporters

TPD

N N

-NPB HOMO: -5.4 eV

LUMO: -2.4 eV

N

N N

N

Spiro-TAD

Material Tg/0C HOMO (eV)

LUMO (eV)

T1 (eV)

TPD 61 -5.5 -2.3 2.3α-NPB 99 -5.4 -2.4 2.4Spiro-TAD 133 -5.4 -2.5 2.4

4.0

2.0

3.0

6.0

5.0

7.0

-2.4

-5.4

-6.02

E/eV

α-N

PB

-2.4

-5.8

HTS

-01

-5.8

-2.1

-2.52

HTS

-03

HTS

-02

-2.4

-5.7

HTS

-04

-2.3

-5.7

HTS

-05

HTS

-06

-5.4

-2.44

-5.7

-2.54

HTS

-07

-2.2

-6.06

HTS

-08

HTS

-11

-5.97

-2.81

-2.4

-5.7

HTS

-10

HTS

-12

-5.17

-2.23

-2.6

-5.97

HTS

-13

2.7 eV

2.0 eV

2.4 eV2.7 eV

2.8 eV

2.4 eV

3.1 eV

2.8 eV

3.1 eV

TCTA Ir(piq)3 Ir(ppy)2

-acacFIr(pic) Ir(dbfmi) HTS-11HTS-08-NPB HTS-04

Triplet Energy Level

Trip

let

Ener

gy

2.67 eV

TPBi

N

Ir

3

O

O

CH3

CH3

N

Ir

2

N

O

O

N

F

FN

F

F

Ir

N

N

O

Ir

3

Ir(piq)3 Ir(ppy)2acac FIr(pic) Ir(dbfmi)

-4.8 eV

-NPB

-2.4 eV

-5.4 eV

-2.4 eV

-5.7 eV

HTS-4

-2.2 eV

-6.1 eV

HTS-8

-2.8 eV

-6.0 eV

HTS-10 HTS-11

-2.4 eV

-5.7 eV

-2.8 eV

-5.8 eV

TPBi

-2.7 eV

-6.2 eV

-5.2 eV

ITO

PEDOT:PSS

-2.9 eV

LiF/Al

HOMO-LUMO values of Hole Transporters

-3.0 eV

-5.3 eV

TCTA:TPBi

Ir(ppy)2acac

Solution processable(Chlorobenzene)

Energy band diagram

Thermal

evaporation

TCTA:TPBi :

Ir(ppy)2acac

2.8 eV

5.8 eV

ITO

4.8 eV

TPBi

2.7 eV

6.2 eV

3.0 eV

5.3 eV

LiF/Al

2.9 eV

NPB

PEDOT:PSS

5.2 eV

2.3 eV

5.4 eV

HTS-08 HTS-011

2.2 eV

6.1 eV

2.4 eV

5.7 eV

Solution process

(Chlorobenzene base)

Thermal

evaporation

NPB : Tg = 99 ℃

HTS-08 : Tg = 135 ℃

HTS-011 : Tg = 124 ℃

Chlorobenzene : b.p = 131 °C

HTS-08

HTS-08

Device structure: ITO/PEDOT:PSS(40 nm)/HTS/TCTA:TPBi(3:7):Ir(ppy)2acac (10 %)(20 nm)/TPBi(30 nm)/LiF(0.5 nm)/Al

Solution Processed Devices

HTS-08

HTS-8 in Chlorobenzene(Normal light)

HTS-8 in Chlorobenzene(Under UV light)

HTLVT

(V)

VD

(V)

Maximum @1000nits @10000nits

C/E

(cd/A)

P/E

(lm/W)

C/E

(cd/A)

P/E

(lm/W)

C/E

(cd/A)

P/E

(lm/W)

NPB ~50 nm 2.48 4.66 58.93 68.07 47.02 31.70 35.89 18.93

HTS-008 ~10 nm 3.01 4.75 40.66 25.85 38.92 25.73 36.49 15.77

HTS-011 ~10 nm 2.65 4.11 70.75 69.29 68.95 52.71 58.81 29.07

Voltage (V)

-4 -2 0 2 4 6 8 10

Lo

g C

urr

en

t D

en

sit

y (

mA

/cm

2)

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

NPB ~50nm

HTS-08 ~4000rpm

HTS-011 ~10nm

Voltage (V)

0 2 4 6 8 10

Lu

min

an

ce (

cd

/m2)

0

5000

10000

15000

20000

NPB ~50nm

HTS-08 ~4000rpm

HTS-011 ~10nm

Luminance (cd/m2)

0 2000 4000 6000 8000 10000

Cu

rren

t E

ffic

ien

cy (

cd

/A)

0

10

20

30

40

50

60

70

80

NPB ~50nm

HTS-08 ~4000rpm

HTS-011 ~10nm

Luminance (cd/m2)

0 2000 4000 6000 8000 10000

Po

wer

Eff

icie

ncy (

lm/W

)

0

10

20

30

40

50

60

70

80

NPB ~50nm

HTS-08 ~4000rpm

HTS-011 ~10nm

NPB ~50 nm

HTS-08 ~10 nm

HTS-011 ~10 nm

NPB ~50 nm

HTS-08 ~10 nm

HTS-011 ~10 nm

NPB ~50 nm

HTS-08 ~10 nm

HTS-011 ~10 nm

NPB ~50 nm

HTS-08 ~10 nm

HTS-011 ~10 nm

Device structure: ITO/PEDOT:PSS(40 nm)/HTS/TCTA:TPBi(3:7):Ir(ppy)2acac (10 %)(Total thickness 20 nm)/TPBi(30 nm)/LiF(0.5 nm)/Al

HTS-11

HTS-08

-NPB

HTS-08

Luminance/

cd m-2

Improvement in

current

efficiency

Improvement in

Power

efficiency

1000 47% 66%

10000 64% 54%

Improvement of efficiency of HTS-11 over -NPB (VTE)

1.0

0.5

Company L

-5.5-6.0-6.5

Company M

HTS-001

10-2

Mobility / cm2V-1s-1

1

2

3

Lifetime

Vop/V-NPB

eV/HOMO

0.1

2.5

2.4

HOLE Transporters

10-5

10-4

10-3

Super HTL-00X

200 300 400

Tm / °C

Tg / °C

-5.0

eV/LUMO

2.3

2.2

2.0

10-1

Company H

-NPB

4

Typical Energy Level Diagram