(133g) Silicon Nanocrystal Quantum Dots

Synthetic nanocrystal chemistry has evolved to produce a variety of materials that are potentially useful in a range of electronic and optical applications. Interest in these materials derives largely from their size-tunable properties. This talk will focus on the synthesis of colloidal silicon (Si) nanocrystal quantum dots and their optical properties. Si is one of the most commercially important semiconductors, but is a poor light-emittier. Si nanostructures on the other hand emit light with relatively high efficiency with color that can be tuned from the near infrared into the visible spectrum by changing size. We have been developing a variety of colloidal synthetic routes for this class of materials that yields size and shape control along with good long-term stability in the presence of water and oxygen (Si is highly susceptible to oxidation). In this talk, the fundamental chemical and photophysical properties of these materials will be described, as well as the use of Si nanocrystal quantum dots for multiplex biological cell imaging using two-photon time-gated microscopy techniques and strategies to enhance the light absorption cross-section of Si quantum dots by decoration with light-absorbing chromophores.