Organic LEDs

- Organic light-emitting devices (OLEDs) are new light sources that find applications in flat panel displays and solid-state lighting. Our research in this area is highly multidisciplinary and focuses on the following key aspects:

- Development of new molecules and polymers with optimized stability, optical, electrical, and structural properties. New chemistries are exploited to add functionality such as easy photopatterning capabilities, for instance.

- Insertion and testing of the new materials in devices with novel architecture to maximize luminance, efficacy, lifetime, and operation at high temperature.

- Some examples of past accomplishments in this area in our group include anthracene- and phenanthrene-based materials as well as thiazole derivatives, etc.

Plastic Solar Cells

- Organic photovoltaic cells like their inorganic counterparts convert optical power into electrical power. Their paper-thin form factor, their lightweight, and their flexibility provide them with unique properties that can be applied in innovative niche applications.

- Ultimately, the possibility to coat organic materials into large-area films at low cost could in the longer term provide economic solutions to solar energy conversion.

- In the near term, the objective of our research is to focus on the optimization of the power conversion efficiency through the development of new materials with high carrier mobility that self-assemble into highly ordered phases, and the optimization of interfaces.

- Some examples of past accomplishments in this area in our group include, the modification of donor and acceptor materials as well as donor-acceptor amphiphilic block copolymers, etc.

OFETs

- Organic or some oxide field-effect transistors (FET) that are prepared by low-cost processes such as printing are expected to play an important role in advance of electronic devices that can benefit from thin, flexible form factors and are akin to ultralow fabrication cost.

- Our research in this area focuses on the following key aspects:
> Development of new electron and hole transport materials with high mobility.
> Optimization and modeling of discrete active and passive devices such as field-effect transistors, analog transistors, inverters, ring oscillators, and logic gates.

- Some examples of past accomplishments in this area in our group include, the modification of p-type materials and n-type materials as well as ambipolar block copolymers, etc.

Functionalization of Carbonaceous Solids & Advanced Materials Chemistry

- Carbon does not stop amazing us – again and again. For many years, elemental carbon, found in sp2 bonded graphite or sp3 bonded diamond, was believed to be well understood. The complexity and importance of organic chemistry reflect the fact that chemically functionalized carbon, often forming sp bonded chains, dominates our world, disguised as clothing, medication, or gasoline. Without carbon, the key player in molecular biology, our life would be different, or not exist in its complexity. The picture emerging from findings across different disciplines suggests that form determines function.

- Carbon is a real champion, with its layered sp2 allotrope being as stable as the sp3 bonded crystalline diamond and, even without functional groups, almost as stable in sp bonded chains. In addition, the design and synthesis of new materials (conjugated materials) is a major focus of research in our group as well.

- Our research in this area focuses on the preparation of solution-processable carbonaceous solids (fullerenes, graphite materials, and etc.) via chemical functionalization on their surface. Besides, currently, we are emphasizing various chemistry of materials.

Collaborated Research Teams

• Fred Wudl

  Chemistry & Biochemistry, University of California at Santa Barbara (USA)

• Alan J. Heeger 

  Center for Polymers and Organic Solids, University of California at Santa Barbara (USA)

• Taek Seung Lee

  Graduate School of Energy Science and Technology, Chungnam National University

• Jin Young Kim

  Department of Energy Engineering, Ulsan National Institute of Science and Technology

• Won-Youl Choi

  Department of Metal and Materials Engineering, Kangnung-wonju National University

• Shinuk Cho

  Department of Physics, Ulsan University

• John R. Reynolds

  Center for Organic Photonics and Electronics, Georgia Institute of Technology (USA)

• Yongfang Li

  CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences (China)

• Joon Hak Oh

  Department of Chemical Engineering, Pohang University of Science and Technology

•  Hyesung Park

  Department of Energy Engineering, Ulsan National Institute of Science and Technology

• Yong-Young Noh

  Department of Energy and Materials Engineering, Dongguk University

• Sung Heum Park

  Department of Physics, Pukyong National University