BUCKY BALL AND QUANTUM DOT DOPED POLYMERS - A NEW CLASS OF OPTOELECTRONIC MATERIALS

After the recent synthesis of fullerene carbon clusters, we have succeeded in synthesizing an approximately 15 angstrom pyramid-shaped CdS cluster (quantum dot). Here we focus on the photoconductive properties of fullerene and CdS cluster doped polymers. Fullerenes (C60 and C70) are very effective dopants for enhancing the photoconductivity of a variety of polymers such as polyvinylcarbazole. Photogeneration and transport measurements show that these fullerene-doped polymeric photoconductors are as good as many commercial photoconductors. The mechanism of photoconductivity and the unique role of fullerene will be discussed. The largest single-sized semiconductor cluster has been synthesized and crystallographically characterized recently. This cluster has an 82 atom tetrahedral core of cubic phase CdS with the overall shape of a pyramid. Its preparation and structure will be discussed. Polymers doped with this CdS cluster, and other semiconductor nanoclusters, show excellent photoconductivity and represent a new class of optoelectronic materials.