Münster 1999 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

PV: Plenarvorträge

PV III

PV III: Plenary Talk

Wednesday, March 24, 1999, 08:30–09:15, H1

Nanocrystals: from scaling laws to optical, electrical, and biological applications — •Paul Alivisatos — Department of Chemistry, University of California at Berkeley , USA

Significant advances have occurred in the chemical synthesis of colloidal nanocrystals. Nanocrystals of metals, semiconductors and dielectrics of uniform size and high quality can now be prepared and manipulated. The fundamental physical properties of these crystals depend strongly on the size, according to scaling laws. CdSe and InAs are examples of semiconductors which can be made as nanocrystals of high quality. Semiconductor nanocrystals exhibit strongly size dependent emission spectra, due to the quantum size effect. Further, the nanocrystals have nearly continuous excitation spectra above the threshold for absorption. As a consequence, the nanocrystals can be viewed as a new class of chromophore. This talk will focus on recent efforts to exploit these size dependent properties. Examples include polymer/nanocrystal composite photovoltaics, nanocrystal based single electron transistors, and nanocrystals as luminescent probes in biological tagging experiments.