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Beavercreek, OH, United States

Mor G.K.,Materials Research Institute, LLC | Basham J.,Materials Research Institute, LLC | Paulose M.,Materials Research Institute, LLC | Kim S.,Pennsylvania State University | And 4 more authors.
Nano Letters | Year: 2010

Solid-state dye-sensitized solar cells (SS-DSCs) offer the potential to make low cost solar power a reality, however their photoconversion efficiency must first be increased. The dyes used are commonly narrow band with high absorption coefficients, while conventional photovoltaic operation requires proper band edge alignment significantly limiting the dyes and charge transporting materials that can be used in combination. We demonstrate a significant enhancement in the light harvesting and photocurrent generation of SS-DSCs due to Förster resonance energy transfer (FRET). TiO2 nanotube array films are sensitized with red/near IR absorbing SQ-1 acceptor dye, subsequently intercalated with Spiro-OMeTAD blended with a visible light absorbing DCM-pyran donor dye. The calculated Förster radius is 6.1 nm. The donor molecules contribute a FRET-based maximum IPCE of 25% with a corresponding excitation transfer efficiency of approximately 67.5%. © 2010 American Chemical Society.

Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 99.94K | Year: 2007

This Phase I program will use metallized carbon nanofibers to develop a class of electrically conductive structural adhesives and bolt hole fillers to improve the electrical and thermal transport properties of organic matrix composite structures. Metallized carbon nanofibers have the beneficial large aspect ratio of the carbon nanofiber and high electrical conductivity of the metal. They can confer significant electrical conductivity to polymer resins at moderate concentrations. In Phase I, MRI will produce silver- and copper-metallized carbon nanofibers of varying metal compositions. The metallized carbon nanofibers will be integrated with structural adhesive resins to formulate the electrically conductive structural adhesives and bolt hole fillers. An initial screening test will be employed to identify the most promising candidate materials. More elaborate electrical, thermal, mechanical, and lightning strike characterizations will be carried out on samples of selected candidate materials to demonstrate the feasibility of the proposed technology.

Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase II | Award Amount: 849.81K | Year: 2003

This SBIR Phase II program will continue research and development of carbon nanotubes for conductive polymer hybrids. The objective is to develop a multifunctional composite material with significant thermal and electrical conductivity for shielding,electrostatic discharge, thermal management, and energy storage and conversion applications. The approach to the high conductivity is via establishing a carbon nanotube network with effective inter- as well as intra-tube transport property in the polymermatrix. Feasibility of this approach was demonstrated in Phase I program. Resulting polymer-nanotube hybrids exhibited electrical conductivity above 200 S/cm with 15 vol.% loading of nanotubes. They also achieved substantially enhanced thermalconductivity. Proposed Phase II efforts include optimizing the processing conditions and developing a process for manufacturing the conductive polymer hybrids in pilot scales. The polymer hybrid material will also be processed into shaped articles usingconventional extrusion and molding techniques. Their thermal, mechanical, electrical, and morphological properties will be characterized to confirm their processing, structure and property relationships.

Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 100.00K | Year: 2002

"This SBIR Phase I research program will develop a processing scheme for producing polymer-nanotube hybrids with significant electrical and thermal conductivity for multifunctional applications. Using carbon nanotubes to impart transport properties toorganic polymers requires the nanotubes to form a conductive network in the polymer matrix. To obtain high electrical and thermal conductivity, the Phase I research will focus on achieving uniform dispersion of the choice carbon nanotubes, maintainingtheir large aspect ratio during processing, and enhancing inter-tube charge transport properties. The processing scheme will be applicable to a wide range of polymers, including thermoplstic, thermosetting, and high-temperature aromatic heterocyclicpolymers. The resulting conductive polymer-nanotube hybrid material will have applications in shielding, thermal management, electrostatic discharge, corrosion protection, and electro-optical devices such as photovoltaics. The polymer-nanotube hybrids canbe tailored with a wide range of thermal, mechanical, and electrical properties for multifunctional applications in coatings, caulks, sealant, adhesives, fibers, films, sheets, tubes, and large structural components. Potential commercial applications forthe conductive nanocomposite material include shielding, charge dissipation, electrostatic painting, corrosion prevention, thermal management, mechanical reinforcement, and electro-optical devi

Agency: Department of Defense | Branch: Air Force | Program: STTR | Phase: Phase I | Award Amount: 99.33K | Year: 1998

When light radiates from the surface of a man-made object, the radiation is often polarized. The polarization components contain information about the spatial orientation of the surface elements. The polarization components may also reveal the material and surface roughness of the surface elements. Researchers have recognized the potential usefulness of imaging polarization data for target detection and identification. However, only recently has the imaging of polarization data in real time been practical. Physics Innovations Inc. has developed a thermal imaging sensor which images intensity and linear polarization data. In the proposed project, we will develop novel microscale waveplates and sensors which will image, in real time, circular polarization data. Circular polarization imaging is complementary to linear polarization imaging. When radiation, from the smooth surface of a man-made object, is primarily thermal emission, then linear polarization is significant. When the radiation is primarily reflection off the surface, then circular polarization is expected to be significant. The proposed sensor can be compact and would be suitable for use for target discrimination in ballistic missile defense systems. This sensor also has applications in synthetic vision for aircraft and automobiles, remote sensing, and quality inspection in circuit board manufacturing.

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