Blinking of single molecule emission under the fluorescence microscope.

Optical Nanostructures and Organic Semiconductors
(Prof. Dr. John Lupton)

Light-harvesting action spectroscopy of single tetrapod-shaped semiconductor nanoparticles. Three different cases of band alignment at the CdSe/CdS interface can be identified in the plots of emission energy versus excitation energy.

We aim to use optical techniques such as time-resolved luminescence and fluorescence microscopy to correlate the physical structure of an object with its electronic properties. Examples of materials studied include organic semiconductors, in particular pi-conjugated polymer molecules, semiconductor colloidal nanocrystals and metallic nanoparticles. These materials can all be interpreted as individual nanostructures, where the physical shape and arrangement in space directly impact on electronic characteristics and the underlying light-matter coupling.

The approach of the group bridges current thrusts in mesoscopic physics, in particular in quantum dot spectroscopy, with open questions in biological, chemical and polymer physics. The formation, migration and dissipation of single charges and excitons is tracked optically in individual nanostructures. Ultimately, we aim to develop a toolbox to design new functional materials from the bottom up.

Lupton’s Homepage

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