Research Breakthrough

Near-infrared organic light-emitting diodes with very high external quantum efficiency and radiance

Led by Professor Pi-Tai Chou, NTU-CEMAD developed a new theoretical concept incorporating the self-assembly of molecules in optimum orientation to breakdown the long-standing restriction of molecular emission in the near infrared (NIR) region, dubbed as energy gap law. Accordingly, they developed highly efficient NIR organic light emitting diodes (OLEDs), for which the peak emission wavelength at 740 nm and unprecedented PLQY of 81% are due to the exciton-like emission among the molecular aggregate, greatly suppressing the exciton-optical phonon coupling. The resulted external quantum efficiency of 24 ± 1% and maximum radiance of (3.6 ± 0.2) x 105 mW·sr-1·m‒2 set up the world record that is 10 times higher than those have been reported. This leading concept and technology can be applied to any ingeniously design molecular system to broaden the spectrum of scope. Future perspective for NIR OLEDs is far-reaching, which can potentially be applied in NIR phototherapy, bio-imaging, photodetector, car sensor and plant growth in agriculture. Paper: Nature Photonics. 2016, DOI: 10.1038/NPHOTON.2016.230

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Professor Pi-Tai Chou's research team synthesized a series of donor-acceptor coordinated Pt(II) complexes to unveil the ordered solid-state packing arrangement, as highlighted by the edge-on preferred orientation in the vacuum-evaporated thin films. They are trying to reach the unprecedented ~ 1000 nm emission with high performance OLEDs. This leading concept and technology can be applied to any ingeniously design molecular system to broaden the spectrum of scope. (Source: Ministry of Science and Technology, Department of Natural Sciences and Sustainable Development)

News and Events

  • Professor Pi-Tai Chou obtained the 2015 TWAS Prize, for his distinguished contribution to fundamental photochemistry through electronically excited-state photodynamics of organic and organometallic materials in condensed phases.


The 248th ACS National Meeting and Exposition,San Francisco (August 10-14, 2014)

In this meeting, there were 29 technical divisions and nine committees in original programming over 1,013 half-day oral sessions and 168 poster sessions, including Sci-Mix. More than 7,400 papers were presented, and nearly 4,400 poster presentations took place at the meeting. One of two organizers for the proton transfer seesion is Professor Pi-Tai Chou, and the session is partly supported by YEN-CHING-LIN Industrial Research Center, National Taiwan University and TopGiga Material.

The cartoon on the meeting poster (as shown on the picture) is to indicate that a proton (H+) is moving from Taiwan to USA, ymbolizing the core issue presented in the proton transfer session.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 161,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. For details, please refer to 248th ACS National Meeting's final program.

The 7th Aseanian Conference on Dye-sensitized and Organic Solar Cells, Taipei (October 26-29, 2012)

The conference took place at Liberal Education Classroom, National Taiwan University, Taipei, more than 300 papers are expected to be presented in oral and poster sessions covering frontline research of Dye‐sensitized and Organic Solar Cells. In this coming DSC‐ OPV7, many world-renowned scientists Prof. Michael Grätzel, Joseph T. Hupp, James Durrant, Hiroshi Segawa, Juan Bisquert, and Mercouri G. Kanatzidis gave speech in the plenary section.

For details, please refer to DSC-OPV7 Official Website.