CEATEC 2021 (October 2021)

Flexible Organic Electronics Technologies(OLED, OPV, etc.)
We have various technologies and equipment for fabricating flexible
organic electronics devices (OLEDs, OPV, etc.).
Using these technologies, we collaborate with industrial companies, aiming
at practical developments for actual products.
This material reviews our technologies and equipment for flexible organic
electronics devices (OLEDs, OPV, etc.).
Yamagata University
Innovation Center for Organic Electronics (INOEL)
Research Group for Flexible Technologies (Nakada/Furukawa/Yuki/Koden)
http://inoel.yz.yamagata-u.ac.jp/F-consortium/home.html(Contact) Prof. H. Nakada nakada@yz.yamagata-u.ac.jp
Prof. M. Koden koden@yz.yamagata-u.ac.jp

1Technologies and equipment

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OLED (Organic Light Emitting Diode) fabrication
Materials
Various types of OLED materials
shown below can be applied toOLED devices.
・Small molecular OLED materials
・Polymer OLED materials
・Fluorescent, phosphorescent andTADF materials
・Quantum dot (QD) materials

Processes for organic layers
・Dry process: Vacuum evaporation
・Solution process: Spin-coat, Ink-jet, Spray, etc.

Vacuum deposition

Ink-jetSpin-coat

Wet cleaning

Plasmacleaner

Device structure
Various types of OLED devices canbe fabricated.
・Bottom emitting OLED・Top-emitting OLED・Transparent OLED
(Both side emitting)・Multi-photon
・White emitting

Spray3

OPV (Organic Photovoltaic) fabrication
Materials
Various types of OPV materials
shown below can be applied toOPV devices.
・Vacuum deposition materials
・Solution materials
・Quantum dot (QD) materials

Device structure

Processes for organic layers
・Dry process: Vacuum evaporation
・Solution process: Spin-coat, Ink-jet, Spray, etc.

Vacuum deposition

Ink-jetSpin-coat

Wet cleaning

Plasmacleaner

Two types of OPV devices can befabricated.
・Normal structure
・Inverted structure

Spray4

Barrier Layer and Encapsulation
Barrier Layer

Encapsulation

・Inorganic barrier layer: CVD, Sputtering,
ALD
・Inorganic/organic alternatingly stacked
barrier layer

Various encapsulating technologies areapplied.
・Common encapsulation with desiccant
・Flexible all-solid type encapsulation
DesiccantN2
CathodeOrganic layers
Anode

R2R sputtering andALD
CVD（Atomic Layer Deposition）

Sealant

Sealant

Counter Glass substrate

Sheet-type lamination

Substrate
Flexible substrate

Resin
CathodeOrganic layers

Anode
Flexible substrate

Sputterig

Ink-jetRoll-type lamination5

有機EL（OLED）, 有機薄膜太陽電池（OPV）試作
大面積有機EL
Large size OLED devices can be fabricated.
The maximum substrate size: 30cm×30cm

フレキシブル有機EL
Flexible OLED devices with various
designs can be fabricated.

OLED vacuum evaporationequipment “ELVESS” (Tokki)

有機膜膜太陽電池
OPV devices can be fabricated.

OLED on 30×30cm
glass substrate
6Evaluation of OLED Materials and Devices
Emission uniformity

Device characteristics

1.0E+041.0E+02
1.0E+01

Luminance (cd/m2)

Uniformemission

・OLED device characteristics areevaluated.
* I-V characteristics* L-I characteristics* Emission spectrum, etc.
Current density (mA/cm2)

・Emission quality such as uniformity,
defects, etc. of OLED devices areevaluated by visual microscopic
observations.

1.0E+00
1.0E-01
1.0E-02
1.0E-03

1.0E-04
1.0E-05
1.0E-060246

1.0E+03
1.0E+02
1.0E+01
1.0E+00

I-V
1.0E-01
characteristics
1.0E-03 1.0E-02 1.0E-01

Non-uniformemission withdefects

Intensity (A.U.)

Voltage (V)Current densi

10.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0Emission
spectrum
300

400

500

600

700

800

Wavelength (nm)7Lifetimes of OLED devies
Driving lifetime

Storage lifetime

Luminance (normalized)

The reduction of emission intensity of
OLED devices under constant current
driving is evaluated.

The change of emission is observed after
storage test with high temperature andhigh humidity.

100%
80%
60%

40%
20%
0%

0500

1000 1500 2000
Time (hour)

2500

3000

Initial emission(No decfect)

Emission after
storage test
(Dark spot)

Driving lifetime

8Evaluation of OPV
Equipment

OPV device

Solar simulator
Newport MODEL 66902

OPV characteristics

１SUN(1000W/m2)
AM1.5 room temp.
About 100,000 LUX
9Other evaluaitons
Bending tests

Analysis

The influences of various bending stresson device characteristics, barrier
properties, etc. are evaluated using
three types of bending equipment.

Other evaluations can be used, basedon the request from collaboratingcompanies.
(Example)・Ionization potential
・Defect analysis
・SEM, AFM
・3D profile

U-shape sliding

Ionization
potentialFolding

Both-sidebending

AFM

ﾊｲﾌﾞﾘｯﾄﾞｺﾝ
ﾌｫｰｶﾙ顕微鏡10Fabricated flexible organic electronics
devices (OLED and OPV)

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Flexible OLEDs on ultra-thin glass

Ultra-thin glass withbottom electrodes

Counter substrate
Protecting layer
Al (100nm)

Collaboration

DPB:Liq (25wt%) 43.5nm
Alq:G-dopant (1.5wt%) 30nm
HTL (40nm)

MoO3 (10nm)
ITO
Ultra thin glass (50mm)
Devise structure

Nippon Electric Glass, etc.

Pubrication⚫ T. Furukawa, M. Koden, IEICE Trans. Electron, E100-C,
949 (2017).
⚫ T. Nakagaki, T. Kawabata, H. Takimoto, T. Furukawa,
IDW’19, FLXp1-9L (2019).
⚫ T. Furukawa, N. Kawamura, T. Noda, Y. Hasegawa, D.
Kobayashi, M. Koden, IDW’17,FLX6-2 (2017).
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Flexible OLEDs on stainless steel foil
Flexible substrate

Barrier resin
Semi-transparent cathodeOrganic layers(plural layers)
ITO
Ag alloy
Planarization layer (3mm)
Stainless steel foil (50mm)

Stainless steel foil of NIPPONSTEEL CORPORATION GROUP

Collaroration

NIPPON STEEL CORPORATIONNIPPON STEEL Chemical & Material Co., Ltd.

Publication⚫ Y. Hagiwara, T. Furukawa, T. Yuki, S. Yamaguchi, N. Yamada, J. Nakatsuka, M. Koden,
H. Nakada, IDW’17, FLXp1-9L (2017).
⚫ M. Koden, T. Furukawa, T. Yuki, H. Kobayashi, H. Nakada, IDW/AD’16, FLX3-1 (2016).
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Flexible OLEDs on barrier film
Insulator(with particles)
Flexible film
Barrier layer
AEF barrier resin
CathodeOrganic layers

Ag

Flexible film
Barrier layer
AEF barrier resin
CathodeOrganic layers(plural layers)(plural layers)

IZO
Barrier layer
PEN film (50mm)

IZO
Barrier layer
PEN film

Collaroration

TEIJIN LIMITED, etc.

Publication⚫ K. Taira, Taiga Suzuki, W. Konno, H Chiba, H. Itoh, M. Koden, T. Takahashi, T.
Furukawa, IDW’18, FLX2-4L (2018).
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Concept samples using flexible OLED device

Flexible substrate

Adhesive resin
CathodeOrganic layers(plural layers)
TCO (Transparent Conducting Oxide)
Barrier layer
Flexible substrate

Collaroration

KOMORI Corporation / TAKEDA PRINTING CO., LTD.

Publication⚫ Yamagata University； “JFlex2020” (Jan. 2020 / Tokyo).

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Flexible OLEDs on EXPEEK® barrier film

Device size: 50 × 50mm
Emission area: 32 × 32mm
Collaroration

KURABO INDUSTRIES LTD.

Publication⚫ T. Yuki, T. Nishikawa, M. Sugimoto, H. Nakada, M. Koden, IDW’20, FLX2-3 (2020).
⚫ Yamagata University； “JFlex2020” (Jan. 2020 / Tokyo); “JFlex2019” (Jan. 2019 / Tokyo).
⚫ KURABO; “7th Fine Plastic Exhibition” (Dec. 2018 / Tokyo), “SEMICON Japan 2018” (Dec. 2018 / Tokyo).
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Flexible OLEDs with TFEL

Collaroration

TOYO INK SC HOLDINGS CO., LTD.

Publication⚫ Yamagata University； “JFlex2020” (Jan. 2020 / Tokyo); “JFlex2019” (Jan. 2019 / Tokyo).
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Flexible OLEDs with laminating encapsulation
Flexible substrate
AEF barrier resin

CathodeOrganic layers(plural layers)
Transparent electrodeFlexible substrate
Collaroration
Ajinomoto Co., Inc. /Ajinomoto Fine-Techno Co., Inc.

Publication⚫ Yamagata University；“JFlex2019” (Jan. 2019 / Tokyo).

Exhibited in “Printable Electronics
2018” exhibition (Feb. 2018, Tokyo)
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Flexible OLED with transparent electrode of Ag nanowire and conducting polymer

Flexible OLED without ITO was successfully fabricated.
Metal foil [*1]Encapsulating layer [*1]
CathodeOrganic layers
Conducting polymer
AgNW
Ultra-thin glass (50mm) [*2]Protecting film [*3][*1] Supplied from Ajinomoto Fine-Techno[*2] developed by Nippon Electric Glass[*3] developed by Mitsubishi Plastics
Publication

Panel size: 50mm x 50mm
Emission area: 32mm x 32mm

⚫ M. Koden, T. Furukawa, T. Yuki, H. Kobayashi, H. Nakada, IDW/AD’16, FLX3-1 (2016).
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Flexible OLEDs with printing non-ITO electrodeFlexible OLED without ITO was successfully fabricated.
✓Substrate size : 50mm X 50mm
Collaboration by:✓Emission aria : 32mm X 32mm
✓Yamagata University✓Dai Nippon Printing✓DIC✓Komori Machinery✓SERIA✓Taiyo Kikai

Metal foil [*]Encapsulating layer [*]CathodeOrganic layers[*] supplied from Ajinomoto
Fine-Techno

Ultra-thin glass (50mm)
Transparent
conducting polymer
Gravure off-set
Flexography
printing
printing
Ag

Insulator
Screenprinting

T. Furukawa, N. Kawamura, M. Sakakibara, M. Koden, International Display
Manufacturing Conference (IDMC’15), S4-4 (2015).
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OLEDs with metal-mesh electrodesubstrate：60mm×100mm

Substrate: Glass

Substrate: PEN

Al (Cathode)Organic layers(plural layers)
PEDOT:PSS

Cu meshResin
Substrate (Glass or film)
Collaboration

Toyo Aluminium K.K., Prof. Takeshi Sano (INOEL, Yamagata University)

Publication⚫ M. Koden, N. Kawamura, T. Yuki, H. Nakada, R. Waguri, K. Den, R. Nakao, H. Minamiyama,
The 31th Meeting of Japan OLED Forum, S7-2 (2020).
⚫ R. Waguri, K. Den, R. Nakao, H. Minamiyama, MES2020, 1B1-2 (2020).
⚫ Yamagata University； “JFlex2020” (Jan. 2020 / Tokyo), “TCTJAPAN” (Jan. 2020 / Tokyo,“JFlex2019” (Jan. 2019 / Tokyo).

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OLEDs with on-demand patterns

CollaborationPublication

TOYO INK SC HOLDINGS CO., LTD.
⚫ M. Sugimoto, Y. Fukuchi, H. Tsuruta, M.Koden, H. Nakada, T. Yuki, A-COE 2021, PA-17 (2021).

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Printed flexible OPV fabricated roll-to-roll (R2R) processes
Features of flexible OPV◼can be applied to windows etc. due to the transparent feature.
◼thin, light weight and un-breakable due to flexible and film
◼applied to various places such as windows, walls, etc. by double-sided tape etc.
Developed technologies◼Fabricated by roll-to-roll (R2R) printing◼Width:30cm、Length>1m◼Fabrication processes
1) Transparent electrode (TCO)
deposition
2) TCO patterning
R2R3) Cleaning of substrateprinting
4) Printing of ETL（R2R）
5) Printing of active layer（R2R）
6) Printing of HTL（R2R）
7) Printing of electrode（R2R）
Structure of flexible
8) Current collection9) Encapsulation
Collaboration

MORESCO Corporation / ideal star inc.

Publication⚫Yamagata University； “JFlex2020” (Jan. 2020 / Tokyo).
⚫Yamagata University; “PVEXPO 2021”」（Mar. 2021 / Tokyo).
⚫Yamagata University； Press Release 2019.11.6.
⚫MORESCO； Press Release 2019.11.6.

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Summary
Our technologies on flexible organic electronics devices (OLED,OPV, etc.) contribute practical R&D in industrial companies bycollaborations using our rich knowledge and skills.
Please do not hesitate to contact with us.
(Contact)
E-mail： nakada@yz.yamagata-u.ac.jp
E-mail： koden@yz.yamagata-u.ac.jp

Research Group for Flexible Technologies(Nakada/Furukawa/Yuki/Koden Group)
Innovation Center for Organic Electronics (INOEL)
Yamagata University
URL：https://inoel.yz.yamagata-u.ac.jp/F-consortium/home-e.html
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