Title: OLED and OPV Technologies – Prospects and Challenges
Speaker: Ching W. Tang, Member of the United States National Academy of Engineering, Doris Johns Cherry Professor at University of Rochester, and Honorary Professor of SCUT
Time: 4:00 p.m., June 6, 2013
Venue: Lecture Theatre, Second Floor, Shaw Building of Humanities, SCUT North Campus
Sponsor: School of Materials Science and Engineering
Abstract: Organic light emitting diode (OLED) and organic photovoltaics (OPV) are the two most advanced devices in the field of organic electronics. OLED, because of its many intrinsic performance advantages, is emerging as a viable alternative to the liquid crystal display (LCD) and poised to become the next-generation display technology. OPV is being actively developed as a low-cost alternative to conventional solar cells based on silicon and other inorganic semiconductors. Recent advances in achieving power conversion efficiencies greater than 10% in OPV devices have significantly boosted their prospects for practical applications. Both OLED and OPV are based on the heterojunction device structure discovered some 25 years ago, but the development paths leading to their prospective applications are distinctly different. In this talk the evolution of OLED and OPV as potentially disruptive technologies and the lessons learned from discoveries to commercialization will be described along with their future prospects and challenges.
Introduction to Professor Ching W. Tang:
Selected Honors & Awards:
Wolf Prize in Chemistry (2011)
Honorary Doctorate, Shanghai University (2010)
Lifetime Achievement Award, University of Rochester (2010)
Daniel E. Noble Award, IEEE (2007)
Member of the U.S. National Academy of Engineering (2006)
Humboldt Research Award, Humboldt Foundation, Germany (2005)
American Chemical Society Award for Team Innovation (2003)
Fellow, Society for Information Display (2002)
Inventor of the Year Award, Rochester Intellectual Property Law Association (2002)
Jan Rajchman Prize, Society for Information Display (2001)
Carothers Award, American Chemical Society (2001)
Northeast Regional Industrial Innovation Award, American Chemical Society (2001)
Eastman Innovation Award, Eastman Kodak Company (2000)
Fellow, American Physical Society (1998)
Research Experitse:
Organic Electronics; Thin-Film Devices; Display Technology; Organic Light Emitting Diodes; Organic Solar Cells; II-VI Semiconductors; CdTe Solar Cells; Thin-Film Deposition and Characterization.
Research Overview:
Our research is focused on two areas: (1) developing high-efficiency and low-cost solar cells, and (2) advancing the technology of organic light emitting diode (OLED) for display and lighting applications. We fabricate thin-film devices using a suite of vacuum deposition and solution process tools, including vapor deposition of multi-component amorphous organic thin films and close-space sublimation of II-VI semiconductors at high temperature to form crystalline films. We design device architectures - planar, bulk, and graded heterojunctions of organic donors and acceptors - for mediating charge generation, recombination, and transport in OLEDs and organic solar cells. We develop low-impedance contacts for electron and hole injections into semi-insulating materials. Our interest in solar cell work includes the development of methods for fabricating high-efficiency CdS/CdTe solar cells with ultra-thin CdTe films, aiming at significant reduction in material usage. We are also interested in further improving organic solar cell efficiency through design of novel device architectures and material compositions. Another major research effort is to advance OLED technology. Specifically we focus on developing highly stable and efficient white emitters for lighting applications, including light-scattering layers for enhanced light extraction.
Recent Publications:
Irfan; Zhang, M.; Ding, H.; Tang, C. W.; Gao, Y. “Strong Interface p-Doping and Band Bending in C60 on MoOx,” Organic Electronics 2011,12, 1588–1593.
Zhang, M.; Wang, H.; Tian, H.; Geng, Y.; Tang, C. W. “Bulk Heterojuction Photovoltaic Cells with Low Donor Concentration,”Advanced Materials 2011, 23, 4960-4964.
Glowacki, E. D.; Marshall, K. L.; Tang, C. W.; Sariciftci, N. S. “Doping of Organic Semiconductors Induced by Lithium Fluoride/Aluminum Electrodes Studied by Electron Spin Resonance and Infrared Reflection-Absorption Spectroscopy,” Applied Physics Letters 2011, 99, 043-305.
Xia, W.; Lin, H.; Wu, H. N.; Tang, C. W. “Effects of High Temperature Annealing on Ultra-thin CdTe Solar Cells,” Thin Solid Films 2011, 520, 563-568.
Kaji, T.; Zhang, M.; Nakao, S.; Iketaki, K.; Yokoyama, K.; Tang, C. W.; Hiramoto, M. “Co-evaporant Induced Crystalline Donor: Acceptor Blends in Organic Solar Cells Effect,” Advanced Materials 2011, 23, 3320-3325.