Synthesis: The synthetic design team focuses on the development of synthetic methodologies for preparation of new materials, ternary materials, and industrially relevant synthetic methodologies. We have demonstrated a novel crystal seeding methodology for the preparation of high-yield, low-temperature grown nano-crystalline semiconductors (2-10 nm, 5% rms batch, >5 g quantities) using molecular cluster precursors that cleanly separate the nucleation event from the growth step. We have extrapolated these strategies to allow doping and production of ternary lattices of nanomaterials with both phosphor and magnetic centers in both II-VI and III-V materials.

Materials Spectroscopy: The close interplay among charge, spin, and lattice degrees of freedom in solid state materials is widely believed to play an important role in the properties of materials. For nanoscale materials the surface is also fundamental to the behavior of materials. In our research effort we have correlated the vibrational, structural, and theoretical properties to explore the relationship between structure and transport properties on varying length and time scales for a range of classical solid state materials, CMR, epasolites, and nanoscale materials. Analysis of vibrational, pressure dependence, and photoluminescence data suggest three specific confinement regimes in nanoscale systems. The regimes correspond to the involvement of surface state perturbations to core electronic levels in these materials. Magnetic and optical studies on dilute magnetic semiconductors suggest enhancement of magnetic superexchange between dopant ions in confined system that arises from changes in the nature of coupling in size-restricted materials.

Materials Assembly: Our efforts on engineering next generation nano-material assemblies through bio-scaffolding, organic assembly, or acid base chemistry has allowed development of unique systems. Bio-scaffolding targets the application of DNA, proteins, or a combination of site-specific binding proteins and DNA duplex structures for the assembly of nano-scale materials. While the assembly of nanocomponents by DNA is not new, the use of enzymes to control structure, and probe bio-activity of these constructs is new. In conjunction with this effort, we have explored the use of rigid rod oligomers based on polyacetylene to connect individual nanomaterials and have analyzed the energy transport properties of these systems. Recent studies have shown potential for these materials as memory devices, in fact, we have been able to generate optical write-read/ thermal erase memory images by taking advantage of changes in the nature of energy transfer following thermal fluctuations in the polymer assemblies. We have shown fine-control over the production of polycrystalline mesocscopic lattice composed of a 6:1 ratio of 5 nm Au and CdSe assembled using acid-base equilibria. These materials possess unique opto-electronic properties due to rapid carrier injection following photoexcitation of the sub-components.