题 目：Organic Semiconductor and Optoelectronics: From Single Molecules to Nanowires
报告人：Prof. Ling Zang
USTAR Professor of Nanotechnology
Director, Utah Center of Trace Explosives Detection (UCTED)
Deparment of Materials Science & Engineering
The University of Utah）
报告摘要：Various planar pi-conjugated molecules have been fabricated into one-dimensional (1D) nanostructures, specifically, nanowires. The strong columnar pi-pi stacking thus formed enables 1D enhanced optical and electrical properties, such as long-range exciton migration and charge transport. Depending on the molecular electronic structure and the intermolecular stacking conformation, the exciton diffusion length can be as long as over 100 nm, much longer than that usually expected for the polymer materials, where the poor organization often causes annihilation of the excitons. Long-range charge transport has also been proven by ESR and photoconductivity measurements. Combination of these unique features leads to development of optoelectronic sensors for trace detection of various gas species, including nitro-based explosives and organic amines. The sensing mechanism is primarily based on the modulation of fluorescence emission or the electrical conductivity of the nanowires upon interaction with gaseous analytes.
报告人介绍：Ling Zang, Ph.D., is a USTAR professor of nanotechnology at the University of Utah, with expertise in the fields of nanomaterials and molecular devices. Dr. Zang’s current research focuses on nanoscale imaging and molecular probing, organic semiconductors and nanostructures, optoelectronic sensors and nanodevices, with the long-term goal of achieving real applications in the areas of national security, renewable energy, and clean environment. Before moving to Utah in 2008, Dr. Zang was an associate professor at Southern Illinois University. He was previously an Alexander von Humboldt Fellow at Erlangen-Nuremberg University in Germany, an NSF CAREER Award winner, and a K. C. Wong Foundation Research Fellow. He also holds an adjunct professorship at the Institute of Chemistry, Chinese Academy of Sciences, Beijing, and serves on the editorial board of several scientific journals including the Journal of Nanoengineering and Nanosystems, the Journal of Nanoscience Letters, and Imaging Science and Photochemistry. Dr. Zang has been awarded various federal grants to support his broad range of research in nanoscience and nanotechnology. Beyond the regular faculty duty on campus, Dr. Zang also remains active in organizing and chairing the nanotechnology sessions of various national and international conferences, e.g., Beckman Frontiers of Science Symposium, National Academy of Sciences, AIChE Annual Meeting, NanoUtah Annual Conference, etc. Dr. Zang earned his B.S. in physical chemistry from Tsinghua University in 1991 and his Ph.D. in chemistry from the Chinese Academy of Sciences in 1995.