CAO Yong
2009-10-22 readCount:4777
CAO Yong was born in Changsha, China. He received his Bachelor Degree in Chemistry in former Leningrad University (Russia). Then at 1966, he joined Institute of Chemistry, Chinese Academy of Science (ICCAS), Beijing, and he has been appointed as full Professor of ICCAS since 1986. In 1979-1981 he was visiting scientist in Department of Chemistry (Prof. H. Kuroda Lab of Physical Chemistry 2), Tokyo University (Japan) where he received his PhD degree in chemistry in 1987. In 1988-1990 he was visiting researcher in Institute of Polymer and Organic Solids, University of California, Santa Barbara (Prof. Alan Heeger's group). In 1990 he joined UNIAX Corporation founded by Alan Heeger and Paul Smith. In 1995, he became UNIAX Fellow (lately, DuPont Displays Fellow after acquisition of UNIAX corporation by E. I. du Pont de Nemours & Company, Inc.). Since 1998, he has been appointed as full professor, director of Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, China. He was elected as member of Chinese Academy of Science in 2001. His fields of research include conducting polymers, optoelectronic conjugated polymers and devices (electroluminescent and photovoltaic devices).
Dr. CAO Yong  started his researches in conducting polymers from middle of 1970s. His most important results in conducting polymer research in this period include: realization of polymerization of acetylene by rare-earth catalyst; studies on structure-property relationship in conducting polymers by using well defined oligomers as a model compounds. He also started investigation of dissolution of doped conducting polyaniline by using organic protonic acids at this period. Later in Santa Barbara, with cooperation with Prof. Alan Heeger and Prof. Paul Smith at UNIAX Corporation he continued this research and the idea was developed into a general concept "Counter-Ion Induced Processibility" which lead to solution- and melting-processable conducting polyanilines and their blend with insulating commercial polymers such as polyolefines with extremely low percolation threshold. He discovered polyaniline fully protonated with fuctionalized counter-ions forms liquid-crystalline state in solution. The concept and the related technology created a new way to solve a long time existing problem in conducting polymer research: as results of gaining high conductivity by chemical doping, the conducting polymers become intractable. The concept of "Counter-Ion Induced processibility" is widely accepted in many laboratories in the world and became one of the important research topics in the field of conducting polymers. This work also directly leads to the first flexible polymer light emitting device, which uses soluble highly-conducting polyaniline coated on flexible PET substrate as an electrode. In 1999, CAO and colleagues reported that quantum efficiency of PLEDs can significantly exceed theoretical upper limit: 25% of corresponding quantum efficiency for photoluminescence for strongly bounded singlet and triplet excitons. This result indicates that the achievement of highly efficient emission from polymer LEDs should be possible. The discovery was widely accepted and proved experimentally later by many other main PLED research groups in the world. At South China University of Technology, CAO and coworkers developed a series of new types of electroluminescent polymers which were successfully applied as highly efficient light-emitting and photovoltaic materials. Among it, he is pioneering in design and synthesis of Se-containing narrow band-gap and Si-containing wide band-gap electroluminescent copolymers. He developed highly efficient single chain white-emitting phosphorescent and fluorescent polymers which is targeting on application in solid state lighting. Recently, he reported high energy conversion efficiency (up to 5%) polymer bulk-heterojunction solar cell based on newly developed donor polymer materials. CAO and his group is pioneering in development of water/alcohol-soluble conjugated polyelectrolytes and their application as electron injection layer in light-emitting devices which allow to high work function metal such as Au and Ag as electron injection electrode. Based on this discovery, his group in first time realized light-emitting devices with printable silver paste cathode in replace traditional thermal vacuum deposition. This work paved a way to realize all-printable roll-to-roll fabrication of large-area polymer LEDs. CAO Yong is co-author of approximately 370 scientific papers with h-index of 54 and total citation without self citation of more than 6,000. He is co-inventor of more than 20 US patents in the areas of conducting polymers and optoelectronic polymers and devices.