Professor and Raymon E. and Rosellen M. Lawton Distinguished Scholar in Chemistry
Adjunct Professor of Physics
Associate Director, UW Clean Energy Institute
Ph.D. Physics, University of Cambridge, 2001
(Physical and Materials Chemistry, Nanotechnology)
The principles and tools of physical and materials chemistry are critical to the energy generation and storage problem. Research in the Ginger lab focuses on the physical chemistry of nanostructured materials with potential applications in low cost photovoltaics (solar cells), energy efficient light-emitting diodes, and novel biosensors. In particular, we study conjugated polymers, semiconductor nanocrystal quantum dots, and plasmon resonant metal nanoparticles. We develop and apply new combinations of scanning probe microscopy and optical spectroscopy (including single molecule techniques) to understand the basic science behind these materials and their applications in devices. We assemble these materials into new structures using Dip-Pen Nanolithography and bio-inspired materials approaches. In general we are interested in the interplay between the organizational structure, the electrical properties, and the optical properties of nanoscale materials, especially as applied to problems of solar energy.
Conjugated polymers blends are promising materials for the next-generation of low-cost photovoltaic materials. To better understand these materials, we combine optical spectroscopy and scanning- probe methods to study charge separation, recombination and transport as a function of thin film morphology and interfacial chemistry in thin films of organic semiconductors. Dip-Pen Nanolithography is used to generate templates for controlling nanoscale morphology through surface chemistry. We have developed Time-resolved Electrostatic Force Microscopy (EFM) and conducting-probe AFM techniques to characterize charge generation, transport, and recombination, with spatial resolutions better than 50 nm, and time resolutions that are the fastest in the world using these methods.
In addition to conjugated-polymers, we are also interested in semiconductor quantum dots as optoelectronic chromophores, particularly for harvesting of low energy photons for solar energy applications. Our research simultaneously combines both optical spectroscopy to study charge generation and recombination in thin films, with scanning probe methods to explore how local variations in environment can influence these processes. We also investigate the effects of surface chemistry on the optical and electronic properties of the particles that we synthesize, and also study composites of quantum dots with organics that are made possible with novel organic semiconductors synthesized by our collaborators.
The local electromagnetic field enhancements that occur near metal nanoparticles can be used to tailor the optical properties of nearby chromophores. We use biomaterials and self-assembly methods to create supramolecular clusters of chromophores and metal particles with unique optical properties. These “metachromophores” exhibit optical properties distinct from those that can be obtained with conventional single-component materials and have unique applications ranging from photovoltaics to label free biosensors. We study the assembled structures by using standard absorption and fluorescence techniques, in addition to single molecule fluorescence, single molecule darkfield scattering, and single molecule lifetime measurements.
"Quantum Dot/Plasmonic Nanoparticle Metachromophores with Quantum Yields That Vary with Excitation Wavelength" K. Munechika, Y. Chen, A.F. Tillack, A.P. Kulkarni, I. Jen-La Plante, A.M. Munro, and D.S. Ginger, Nano Letters 11 (7) 2725-2730 (2011).
"Imaging Local Trap Formation in Conjugated Polymer Solar Cells: A Comparison of Time-Resolved Electrostatic Force Microscopy and Scanning Kelvin Probe Imaging" O.G. Reid, G.E. Rayermann, D.C. Coffey, and D.S. Ginger J. Phys. Chem. C 114 (48) 20672-20677 (2010).
"Plasmonic Nanoparticle Dimers for Optical Sensing of DNA in Complex Media" J. I.-L. Chen, Y. Chen, and D.S. Ginger J. Am. Chem. Soc. 28, 9600-9601 (2010).
"Characterizing Morphology in Bulk Heterojunction Organic Photovoltaic Systems" R. Giridharagopal and D.S. Ginger J. Phys. Chem. Lett. v1 1160-1169, (2010).
"Time-Resolved Electrostatic Force Microscopy of Polymer Solar Cells” D.C. Coffey and D.S. Ginger, Nature Materials (2006), 5, 735-740.