Condensed Matter Physics Seminar
Quantum Dots: What Structure Governs Their Photoluminescence Property?
Institute of Materials Science
Semiconductor nanocrystals (NCs) (also called “quantum dots”) have aroused a wide range of scientific and technical interest due to their size tunable physical and chemical properties as a result of quantum confinement effects (QCE). Their size dependent photoluminescence (PL) is under extensive investigations, but the structural factors that govern the PL property are not well understood yet. Etching of CdSe NCs by amines was discovered in the present work and will be discussed in detail to interpret the contradictory observations of the effects of amines on PL efficiency. This chemical etching was further utilized to investigate the structure - PL property relationship of quantum dots and a structural model for high PL quantum dots proposed. Based on this model, we developed a novel synthetic strategy for zinc blende CdSe NCs with high PL efficiency. Characterization of these semiconductor quantum dots and with UV/Vis spectroscopy, Fluorescence spectroscopy, TGA, DSC, XRD, XPS, EDX, TEM and HRTEM will also be discussed. These semiconductor quantum dots have potential applications in biolabeling, counterfeiting, photovoltaics, and solid-state lighting such as light emitting diodes (LEDs).
Thursday, April 13, 2006
Gant Science Complex
(The seminar is followed by coffee/tea, cookies, and an informal discussions.)