Our group works in the areas of Organic Electronics, Plasmon-enhanced Spectroscopy and Biomolecular Sensing. The vision behind our studies of Organic Electronics is to understand easily processed organic materials for inexpensive applications as the active element in light-emitting diodes, thin film transistors and photovoltaic devices. We study the science of light emission, charge photogeneration and charge transport that underpins future applications of polymers in flexible displays, electronic paper and organic solar cells. The techniques we use span the range from transient spectroscopy of excited state relaxation to charge modulation spectroscopy in devices. We work with novel materials such as self-organizing chiral conjugated oligomers, dendritic side group polymers and water-soluble emissive polymers. Our current collaborators in the Organic Electronics area are Man Kit Ng, Esther Conwell and Al Marchetti (Chemistry), Shaw Chen and Ching Tang (Chemical Engineering), Mary Galvin (University of Delaware), Michael Rubner and Tim Swager (MIT), Ralph Young (Eastman Kodak) and Darryl Smith (Los Alamos). Recent accomplishments include single chromophore studies of conjugated polymers, mechanistic work on the salvation of thiophene-containing dendrimers and plasmonic enhancement of organic photovoltaics.
In the biomolecular sensor area, we aim to develop new optical detection approaches based on interactions with nanoparticles, reflectivity, Raman spectroscopy and radiative engineering of fluorescent decay rates. Coupled to our sensing effort, we are studying the basic science of single molecule Raman and fluorescence spectroscopy. Our collaborators in this area are Ben Miller (Dermatology), Todd Krauss and Doug Turner (Chemistry), Hong Yang (Chemical Engineering) and Howard Federoff (Center for Aging). Recent accomplishments include the invention of rapid sequence screening technology based on electrostatic interactions between gold nanoparticles and DNA as well as development of reflective interferometry, a label-free microarray reading technology with high sensitivity.
Integer Charge Transfer States in Organic Light-emitting Diodes: Optical Detection of Hole Carriers at the Anode Organic Interface,"
J. Appl. Phys.
Kinetics and Mechanism of Single-Stranded DNA Adsorption onto Citrate-Stabilized Gold Nanoparticles in Colloidal Solution,"
Conjugated Polymers: Watching Ploymers Dance,"
Plasmon-Enhanced Luminescence and Applications to Organic Electronics,"
Metal Enhanced Fluorescence
Chris Geddes (Ed.), Wiley,
Luminescence quenching by charge carriers in organic light-emitting diodes,"
Digest of Technical Papers - Society for Information Display International Symposium
Plasmon Enhancement of Bulk Heterojunction Organic Photovoltaic Devices by Electrode Modification,"
Appl. Phys. Lett.
Regulation of electronic behavior via confinement of PPV-based oligomers on peptide scaffolds,"
J. Mater. Chem.
Structure and dynamics of single conjugated polymer chromophores by surface-enhanced Raman spectroscopy,"
Conformational reorganization and solvation dynamics of dendritic oligothiophenes,"
J. Phys. Chem. B
Selective quenching of fluorescence from unbound oligonucleotides by gold nanoparticles as a probe of RNA structure,"
RNA-a Publication of the RNA Society
Label-free sensing of binding to Microarrays using brewster angle straddle interferometry,"
Enhancement of Adsorbed Dye Monolayer Fluorescence by a Silver Nanoparticle Overlayer,"
J. Phys. Chem. B
Biomolecular Sensing using Near-Null Single Wavelength Arrayed Imaging Reflectometry,"
Origins of blinking in single-molecule Raman spectroscopy,"
J. of Phys. Chem. B
Enhancement of Platinum Octaethyl Porphyrin Phosphorescence Near Nanotextured Silver Surfaces,"
J. Am. Chem. Soc.
Label-free colorimetric detection of specific sequences in genomic DNA amplified by polymerase chain reaction,"
J. Am. Chem. Soc.
Charge-induced luminescence quenching in organic light-emitting diodes,"
Chemistry of Materials