Quantum chemistry and cyanine dye-sensitization: tuning photophysical properties for advanced applications

This PhD research investigates a special class of colorful molecules called cyanine dyes, which are used in medical imaging, sensors, and potentially, solar cells. When these dyes are combined with nanoparticles—tiny particles thousands of times smaller than a grain of sand—they can form powerful hybrid systems capable of absorbing more sunlight, therefore, being considered a huge promise to improve solar cells efficiency.
However, designing and understanding such systems is extremely challenging. The dyes are very complex, as are the nanoparticles, making their combined properties are difficult to characterize using theoretical models. In this thesis, I use advanced quantum chemistry simulations to explore how changes in the dye structure can dramatically change its optical behavior.
More importantly, I show how these structural changes affect how energy is transferred when the dye is attached to a nanoparticle. This knowledge opens up new strategies for designing dyes with tuned properties for specific applications. Despite the complexity of the systems studied, the results provide an insight for guiding the experimental synthesis of more efficient nanomaterials.