Fisk University

Fisk University
Type Disciplines
Private University Chemistry Composites Fabrication Nanomedicine Quantum Dots
Address Postal Code
Department of Physics
1000 17th Ave. N.
37208
City State / Province
Nashville TN
E-mail Country
USA
Web Phone
link (615) 329-8654
Fax
(615) 329-8634

Fisk University is participating in the $15 Million National Science Foundation 2006 award to Northwestern University for the nation’s first Center for Learning and Teaching in Nanoscale Science and Engineering (NCLT).

NANOPHASE MATERIALS
Nanophase materials research focused on laser ablation and optical trapping techniques for fabricating and spatially manipulating nanoparticles. The nanoparticles of particular interest are quantum dots (semiconductor reduced to a size such that the particle size is smaller than that of the exciton) and metal nanocrystals. Confinement of the exciton leads to a shift in the band gap, which in turn scales with 1/r2 where r is the particle radius. This property has been used for fabricating materials with a size-graded band gap, which have potential applications in solar energy cells. Theoretical calculations indicate that solar energy cells based on size-graded quantum dot structures could have a threefold increase in conversion efficiency.

Driven by the expected increase in conversion efficiency, the Fisk scientists have fabricated size-graded quantum dot structures using pulsed laser ablation and is currently developing them into devices. Optical trapping (also known as laser tweezers) is a technology which is amenable to the manipulation of these small particles. This approach has led to several spinoff discoveries-- demonstrating that optical trapping can be used to separate nanoparticles of different sizes based on the threshold power for affecting trapping, spatially enhancing photoluminescence whereby a particle is held by the optical tweezers and subsequently irradiated with another laser to excite photoluminescence, showing multiple particle trapping in an optical field, and extending the matrix isolation technique to optical trapping for isolating a nanoparticle in a matrix of inert polystyrene beads.

Overall, the marriage between the technique of optical trapping and nanoparticle science is expected to open new doorways of research that will both advance the fundamental understanding of nanoparticles and serve as a tool for nanomaterials fabrication.

CONTINUING NANOSCIENCE EDUCATION
For professional development activities and curricular testing, the Midwestern lead institutions will collaborate with additional partners locally and nationally. Undergraduate course materials will be field-tested and evaluated at multiple sites, including five minority-serving institutions: Alabama A & M University, Fisk University, Hampton University, Morehouse College and the University of Texas at El Paso. Middle-school and high-school modules will be field-tested in the classrooms of award-winning science teachers across the country

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