Handbook of Organic Light-Emitting Diodes

1. Analysis of Degradation by Various Spectroscopic Methods

   • Kazuhiro Marumoto

2. Analysis of Degradation Related to Encapsulation

   • Takahiro Mino, Takashi Miyamoto, Akira Suzuki, Hisashi Takahagi, Atsushi Uehigashi, Yoshiko Ohzu et al.

3. Analysis of Degradation Related to Layered Structures

   • Takahiro Shibamori, Yuji Otsuka, Takashi Miyamoto, Satoshi Miyaguchi, Kyoko Katagi, Hiroshi Ohata et al.

4. Barrier Film Development for Flexible OLED

   • Lorenza Moro, Robert J. Visser, Bill MacDonald, Senthil Ramadas Kumar, Martin P. Rosenblum, Neil Morrison et al.

5. Driving Technologies for OLED Display

   • Yojiro Matsueda

6. Frit Sealing of OLED Displays

   • Robert M. Morena, John F. Bayne, Jamie T. Westbrook, Sujanto Widjaja, Lu Zhang

7. Laser Patterning Technologies

   • Min Chul Suh

8. Low Molecular Weight Materials: Dry Processing

   • Satoru Inoue, Hiroto Itou, Hiroshi Kita

9. Low Molecular Weight Materials: Electron Injection Materials

   • Takayuki Chiba, Yong-Jin Pu, Junji Kido

10. Low Molecular Weight Materials: Electron-Transport Materials

    • Hisahiro Sasabe, Junji Kido

11. Low Molecular Weight Materials: Hole-Transport Materials

    • Hisahiro Sasabe, Junji Kido

12. Low-Molecular-Weight Materials: Hole Injection Materials

    • Hirohiko Fukagawa

13. Low-Molecular-Weight Materials: Wet Processing

    • Naoya Aizawa

14. Outcoupling Technologies: Concepts, Simulation, and Implementation

    • Stéphane Altazin, Lieven Penninck, Beat Ruhstaller

15. Panel Performance of OLED Display

    • Seungbae Lee

16. Physics and Design Principles of OLED Devices

    • Gábor Méhes, Atula S. D. Sandanayaka, Jean-Charles Ribierre, Kenichi Goushi

17. Polymer Materials: Wet Processing

    • Takeshi Yamada

18. Seal Encapsulation: OLED Sealing Processes

    • Stefano Tominetti, Jiabril Gigli, Sheng-Hsu Shih, Yu-Ting Su, J. H. Jou

19. Solution Deposition: Inkjet-Printed OLED

    • Byung Doo Chin

20. Thin Film Encapsulation

    • Robert Jan Visser, Lorenza Moro, Xi Chu, Jerry R. Chen, Peter van de Weijer, Hylke B. Akkerman et al.

This handbook presents a wide range of information regarding the technology of organic light-emitting diodes (OLEDs), from the basic physics of light-emitting devices to the applications for organic-light-emitting technologies, such as OLED displays for mobile phones and large-screen televisions and OLED lighting.
The remarkable advances in the performance of OLEDs reported these days are mainly due to the improvement of organic material design and the enhancement of light extraction. In the first two chapters of this handbook, device and material design strategies aimed at high-performance OLEDs suitable for low power consumption and highly durable applications are addressed. The latest advancements in molecular design are also discussed, including state-of-the-art “thermally-activated delayed fluorescence” technology, which employs a novel concept to move “forbidden” triplet exciton energy back to a singlet state so that 100% internal quantum efficiency can be achieved.
For optimized electrical properties and light emission, OLEDs are normally composed of several layers, each of which plays a different part, such as a hole-injection layer, hole-transport layer, emission layer and electron-transport layer. The design requirements of organic molecules suitable for each layer are discussed.
To manufacture OLEDs, several key technologies are being pursued. The most popular method is vacuum evaporation, which is used in nearly all of the OLED products currently on the market. Several technologies that could improve manufacturing yield and lower processing costs, such as inkjet and roll-to-roll printing, have been proposed and are being actively developed. These device fabrication methodologies are discussed and weighed in terms of their advantages and disadvantages.
The main applications for OLEDs are displays and lighting. Display designs for active-matrix driving and passive-matrix driving, as well as in-pixel and out-pixel compensation, which eliminates luminous non-uniformity, are discussed, along with an analysis of TFT backplane technologies.
The lighting chapter focuses on the principles and advances made in tandem OLEDs comprised of multiple devices in a single stack, which can significantly extend device lifetime. Also, light extraction technology that has boosted OLED efficiency to nearly that of inorganic LEDs is discussed. The subsequent chapter addresses the hot topic of flexible OLED displays and lighting. As the devices are very sensitive to atmospheric moisture, the high-performance barrier films necessary for implementing practical flexible devices are covered.
Organic devices were originally thought to be limited by device lifetimes shorter than those of their inorganic counterparts. However, a white OLED device with a lifetime of tens of thousands of hours has already been reported, which is very close to the lifetime of inorganic LEDs. In closing, the latest degradation mechanism studies on OLEDs are presented, revealing both our current understanding of degradation and the challenges that remain for further improving device lifetimes.

• Department of Applied Chemistry and Biochemistry, Kyushu University, Fukuoka, Japan

  Chihaya Adachi

• Art, Science and Technology Center for Cooperative Research, Kyushu University KASTEC, Fukuoka, Japan

  Reiji Hattori

• Institute for Chemical Research Division of Environmental Chemistry, Kyoto University, Kyoto, Japan

  Hironori Kaji

• Konica Minolta Pioneer OLED, Inc., Konica Minolta, Inc., Tokyo, Japan

  Takatoshi Tsujimura

Chihaya Adachi is director of the Center for Organic Photonics and Electronics Research (OPERA), program coordinator of Kyushu University's Education Center for Global Leaders in Molecular Systems for Devices, and director of the Fukuoka i3 Cneter for Organic Photonics and Electronics. He received his doctorate in Materials Science and Technology from Kyushu University in 1991. After holding positions as a research chemist and physicist at the Chemical Products R&D Center at Ricoh Co., a research associate at the Department of Functional Polymer Science at Shinshu University, a member of the researcher staff at the Department of Electrical Engineering at Princeton University, and an associate professor and professor at Chitose Institute of Science and Technology. He was appointed professor of the Center for Future Chemistry and the Department of Applied Physics, Kyushu University, and became a distinguished professor there in 2010. Since 2013, he has led the JST-ERATO Adachi Molecular Exciton Engineering Project as research director until 2019. He has received a number of honorary awards, e.g., the Commendation for Science and Technology from the Minister of Education, Culture, Sports, Science and Technology, Science and Technology Promotion Category, Studies on Organic Electroluminescence in 2004; SID Fellow Awards in 2014; the Japan Society of Applied Physics Fellow Awards in 2016; and Thomson Reuters Research Front Award 2016.

Reiji Hattori is a professor at the Global Innovation Center, Kyushu University. His work mainly involves technologies of OLED display, electronics paper, touch sensor panel and wireless power transmission. He received his M.S. and B.S. degrees in electrical engineering from Osaka University, Japan, in 1988 and 1986, respectively. He became a research associate at the Department of Electrical Engineering, Osaka University, in 1989 and received his Ph.D. degree from the same university in 1992. He moved to Kyushu University, Fukuoka, Japan, as an associate professor in 1997 and he was promoted to professor in 2009. He is a member of SID, IEEE, IEICE and JSAP. He was awarded Distinguished Paper of SID ’04.

Hironori Kaji is a professor at Kyoto University. He received his Ph.D in inorganic chemistry from Kyoto University in 1994. After his Ph.D, he joined the Institute for Chemical Research, Kyoto University, as an assistant professor, and was appointed an associate professor and full professor in 2003 and 2009, respectively. He was a visiting scientist of the University of Massachusetts from 1998 to 1999 and was a research fellow of Precursory Research for Embryonic Science and Technology supported by Japan Science and Technology Agency from 2002 to 2006. His research interests include fabrications of organic light-emitting diodes, organic and perovskite solar cells, synthesis for device fabrications, development of advanced solid-state NMR methodologies for analysis, and quantum chemical calculations.

Takatoshi Tsujimura is a Konica Minolta Fellow and general manager of OLED business, Konica Minolta Inc. He received his Bachelor of Science and Ph.D. in materials science and engineering from the University of Tokyo and Tokyo Institute of Technology, respectively. He worked at IBM Japan for TFT-LCD development and was selected as one of the "10 best engineers/researchers in 10 best Japanese companies" by Nikkei Electronics Magazine. He demonstrated OLED's capability for large TV and received the SID Special Recognition Award in 2008. He moved to Kodak as a director and developed 100% NTSC white + color filter OLED display, which has become the industry standard for OLED-TV. He is currently a Konica Minolta Fellow and general manager of OLED business, Konica Minolta Inc. He received the SID Fellow Award in 2013. He is an SID executive and served as a SID Japan chapter chair in past. He holds 144 patents worldwide.