Dr. William (Bill) Buhro, chair of chemistry at Washington University in St. Louis, will speak on “Colloidal semiconductor quantum belts, platelets, and magic-size nanoclusters” at 4:30 p.m. today, Monday, April 15, in Room G3 Schrenk Hall. Light refreshments will be provided from 4-4:30 p.m. The seminar is sponsored by the American Chemical Society local section. Bruho, an editor of the journal Chemistry of Materials, published by the American Chemical Society, is an expert in nanomaterials and materials chemistry. The abstract of Bruho’s seminar is given below. More information about Burho is available at http://www.chemistry.wustl.edu/faculty/buhro. For further information regarding Buhro’s visit contact Manashi Nath.

Abstract:
“Pseudo-1D nanocrystals such as quantum wires (QWs) and quantum belts (QBs, nanoribbons) are in principle capable of transporting energy (excitons) and charge over long distances, and thus may have applications in solar-energy conversion and other technologies.
However, excitons and charge carriers in QWs and QBs sample extremely large surface areas and thus have a high probability of encountering surface trap sites, precluding efficient transport.
I will describe semiconductor QBs in which excitons are efficiently delocalized over the entire length of the nanostructures, and the photoluminescence efficiencies are as high as 40%, rivaling those of quantum rods. Crystalline, colloidal CdSe quantum platelets (QPs) are prepared at room temperature. The QBs and QPs are obtained from (CdSe)13 nanoclusters entrained within lamellar-template structures.
Their excellent optical properties result from the smooth facets and effective passivation afforded by the template synthesis, which minimize surface trap-site populations. The isolation and characterization of [(CdSe)13(n-alkylamine)13] derivatives will also be described.”