Speaker:Reuben Collins,Professor of Physics, Editor-in-Chief of Applied Physics Letters, Colorado School of Mines, Golden, CO
Time: 10:00a.m.Tuesday,September 2nd
Transparent metal oxides are used extensively in organic electronic devices as charge selective layers for electron or hole collection. They are also receiving attention in heterojunction silicon solar cell development. The energetics of the interface between the metal oxide and absorber plays a central role in the performance of these devices. This presentation discusses molecular monolayer modification of two oxides of considerable interest, ZnO and NiO. Monolayers of surface-bonded silanes, thiols, and phosphonic acids have been developed on these metal oxide surfaces and characterized with a range of surface sensitive structural, electronic, and optical techniques. The chemistry of the surface bond in each case and tradeoffs between bonding and etching were examined. Control of the surface energy of the metal oxide, which changes the wetting and ordering of the organic at the interface, has been demonstrated. In addition, metal oxide work function can be systematically tuned by more than 1eV by introducing dipolar functional groups. This work function control is reflected in the open circuit voltage of organic solar cells that include the modified metal oxide layers. Support of the National Science Foundation and Renewable Energy Materials Research Science and Engineering Center is gratefully acknowledged.
Reuben T. Collins earned his Ph.D. in Applied Physics at the California Institute of Technology in 1985. For the next 10 years he held increasingly responsible research and management positions at the IBM T.J. Watson Research Center in Yorktown Heights, NY. Taking up an academic appointment in 1994, Prof. Collins moved to the Colorado School of Mines (CSM) in Golden, CO, where he is currently Associate Director of the Renewable Energy Materials Research Science and Engineering Center (REMRSEC) and Professor of Physics.
Research Interests: Condensed matter physics, photovoltaics, nanoscale physics, electronic and optical properties, renewable energy, and magnetic materials.
Professional Activities and Awards: Fellow of the American Physical Society. Center for Revolutionary Solar Photoconversion Distinguished Colleague. Professor Collins was elected 2013 Chair of the APS topical group on Energy Research and Applications. He is a recipient of the Colorado School of Mines Dean’s Excellence Award, the Excellence in Research Award, and is the Faculty Senate Distinguished Lecturer for 2015. He received the award for Outstanding Performance by a Small Business Contractor in Fiscal Year 1998 - DARPA Ultra Electronics Program. He has organized numerous national and international conferences and workshops.