Stephen Ducharme, Professor
Physics & Astronomy
University of Nebraska–Lincoln
310F Jorgensen Hall
Lincoln, Nebraska 68588-0299
Ferroelectric Polymers: Crystalline Langmuir-Blodgett films of poly vinylidene fluoride and its copolymers as thin as one nanometer are the first truly two-dimensional ferroelectrics and have several potential applications. This work involves a multi-disciplinary collaboration with groups led by V. M. Fridkin at the Institute of Crystallography, Russian Academy of Sciences, Moscow; J. Li at the University of Washington; H. Kohlstedt at the Institut fûr Festkörperforschung in Jülich, Germany; S. Kalinin at Oak Ridge National Laboratory; S. Nakhmanson at Argonne National Laboratory; and the J. A. Woollam Co. Collaborations within the NCMN involve groups led by J. M. Takacs (Chemistry), S. Adenwalla and A. Gruverman (Physics), R. Saraf (Chemical Engineering), and Y. Lu (Electrical Engineering).
Fundamental studies focus on the properties of the ferroelectric polymer LB films, such as, the phase diagram, switching dynamics, dielectric properties, properties of nanostructured films, and development of new ferroelectric polymers. Applied studies focus on the application of the ferroelectric polymer LB films to nonvolatile random-access memories, pyroelectric infrared imaging devices, and high-energy-density capacitors. Notable accomplishments include the discovery of two-dimensional ferroelectricity, the first measurements of the intrinsic ferroelectric coercive field and intrinsic switching kinetics, development of a ferroelectric integrated polymer-silicon nonvolatile access memory element, discovery of ferroelectric nanomesas as small as 10 nm high by 100 nm in diameter.
- Jihee Kim, Ph.D., 2008. "Polarization Coupling in Nanostructured Ferroelectric Polymer Langmuir-Blodgett Films"
- Timothy J. Reece, Ph.D., 2007. "Characterization of Metal-Ferroelectric-Insulator-Semiconductor Structures Based on Ferroelectric Langmuir-Blodgett Polyvinyidene Fluoride Copolymer Films for Nondestructive Random Access Memory Applications"
- Matt Poulsen, Ph.D., 2007. "Investigation of Ferroelectric Behavior in Electroactive Polymer Systems"
- Christina Othon, Ph.D. 2005. "Switching Dynamics of Ferroelectric Langmuir-Blodgett Copolymer Films"
- Brad Peterson, B.S., 2004. "Pyroelectric Scanning Microscopy"
- Menjun Bai, Ph.D. 2002. "Structure of Ferroelectric Polymer PVDF/TrFE Copolymer Langmuir-Blodgett Films"
- Vladimir Fridkin (Institute of Crystallography, Russian Academy of Science, Moscow)
- James M. Takacs (UNL Department of Chemistry)
- Shireen Adenwalla, Axel Enders, Alexei Gruverman, David Sellmyer (UNL Department of Physics and Astronomy)
- Jinsong Huang (UNL Department of Mechanical Engineering)
- Yongfeng Lu (UNL Department of Electrical Engineering)
- Serge Nakhmanson (Argonne National Laboratory)
- Herman Kohlstedt (U. of Kiel, Germany).
- UNL Speakers Bureau
- NCMN Outreach and Education Chair
- Kristin Kraemer, Shashi Poddar, Jingfeng Song (Graduate students)
- Susan Cooper, Mitchell Schmidt, Ben Wotruba (Undergraduate Student)
- Steven Wignall, Seward HS teacher (summers)
- Nicholas Reding, Papillion-La Vista HS teacher (summers)
- “Tuning the Energy Level Offset of Donor and Acceptor with Ferroelectric Dipole Layers for Increased Efficiency in Bilayer Organic Photovoltaic Cells,” Bin Yang, Yongbo Yuan, Shashi Poddar, Pankaj Sharma, Rafal Korlacki, Stephen Ducharme, Alexei Gruverman, Ravi Saraf and Jinsong Huang, Advanced Materials 24, 1455-60 (2012).
- “The sweep rate dependence of the electrical control of magnetic coercivity,” A. Mardana, S. Ducharme, S. Adenwalla, J. Applied Physics 111, 07C708 (2012).
- “Homogeneous switching in ultrathin ferroelectric films,” R. V. Gaynutdinov, S. G. Yudin, S. Ducharme, V. M. Fridkin, J. Physics: Condensed Matter 24, 15902 (2012).
- “Electrical Control of Photoluminescence Wavelength from Semiconductor Quantum Dots in a Ferroelectric Polymer Matrix,” R. Korlacki, R. F. Saraf, S. Ducharme, Applied Physics Letters 99, 153112 (2011). (link)
- “Polarization switching at the nanoscale in ferroelectric copolymer thin films,” R. V. Gaynutdinov, S. Mitko, S. G. Yudin, V. M. Fridkin, S. Ducharme, Applied Physics Letters 99, 142804 (2011). (link)
- “Orientational Imaging in Polar Polymers by Piezoresponse Force Microscopy,” Pankaj Sharma, Dong Wu, Shashi Poddar, Timothy J. Reece, Stephen Ducharme and Alexei Gruverman, J. Applied Physics 110, 052010 (2011). (link)
- “Cluster Synthesis and Improved Dielectric Properties of Monodisperse TiO2-Vinylidine Fluoride Oligomer Nanocomposites,” B. Balasubramanian, K. L. Kraemer, Shah R. Valloppilly, S. Ducharme, D. J. Sellmyer, and Stephen Ducharme, Nanotechnology 22, 405605 (2011). (link)
- “Ferroelectric Control of Magnetic Anisotropy,” A. Mardana, S. Ducharme, S. Adenwalla, Nano Letters 11, 3862-67 (2011).link
- “High-Resolution Studies of Domain Switching Behavior in Nanostructured Ferroelectric Polymers,” Pankaj Sharma, Timothy J. Reece, Stephen Ducharme and Alexei Gruverman, Nano Letters 11, 1970-75 (2011). (link)
- “Polarization patterning by laser-induced phase change in ferroelectric polymer films,” C. M. Othon, S. Ducharme, Applied Physics A 104, 727-31 (2011). (link)
- “Efficiency enhancement in organic solar cells with ferroelectric polymers,” Yongbo Yuan, Timothy J. Reece, Stephen Ducharme, Pankaj Sharma, Alexei Gruverman, Yang Yang, Jinsong Huang, Nature Materials 11 (3), 296-302 (2011). (link)
- “Magnetoelectric Effects In Ferromagnetic Cobalt / Ferroelectric Copolymer Multilayer Films,” A. Mardana, Mengjun Bai, A. Baruth, Stephen Ducharme, S. Adenwalla, Applied Physics Letters 97, 112904 (2010). (link)
- “Investigation of State Retention in Metal-Ferroelectric-Insulator-Semiconductor Structures Based on Langmuir-Blodgett (LB) Copolymer Films,” T. J. Reece, A. Gerber, H. Kohlstedt, S. Ducharme, J. Applied Physics 108, 024109 (2010). (link)
- V. Fridkin and S. Ducharme, Ferroelectricity at the Nanoscale: Basics and Applications. (Springer, Berlin, 2014). ISBN 978-3-642-41007-9. Hardcover http://link.springer.com/book/10.1007/978-3-642-41007-9.
- “Ferroelectric Polymer Langmuir-Blodgett Films,” S. Ducharme, S. P. Palto, V. M. Fridkin, L. M. Blinov, Ch. 11 in Ferroelectric and Dielectric Thin Films, Vol. 3 of Handbook of Thin Films Materials, Hari Singh Nalwa, ed. (Academic Press, San Diego, 2002).
- “System and method for improving data acquisition capability in spectroscopic rotatable element, rotating element, modulation element, and other ellipsometer and polarimeter and the like systems,” S. E. Green, C. M. Herzinger, B. D. Johs, J. A. Woollam, S. P. Ducharme. US Patent #5,956,145 issued 21 September 1999. Assignee: J. A. Woollam Co. Inc.
- “Ellipsometer,” S. P. Ducharme, E. H. Machlab, B. D. Johs, J. A. Woollam, UNL and J. A. Woollam Company. U. S. Patent #5,657,126 issued 12 August 1997. Assignee: The Board of Regents of the University of Nebraska.
- “Photorefractive Materials,” S. P. Ducharme, W. E. Moerner, J. C. Scott, R. W. Twieg. U. S. Patent #5,460,907 issued 24 October 1995; Continuation Patent #5,460,907, issued 24 October 1995. Assignee: IBM Corporation.
- “Small Modulation Ellipsometer,” S. P. Ducharme, E. H. Machlab, B. D. Johs, J. A. Woollam, UNL and J. A. Woollam Company. U. S. Patent #5,416,588 issued 16 May 1995. Assignee: The Board of Regents of the University of Nebraska.
- “Photorefractive Materials,” S. P. Ducharme, W. E. Moerner, J. C. Scott, R. W. Twieg. U. S. Patent #5,064,264 issued 12 November 1991; European patent #91309082.5, issued 11 November 1991. Assignee: IBM Corporation.