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Identifier

000413142

Title

Synthesis and characterization of porphyrin derivatives as photosensitizers in solar energy harnessing schemes

Alternative Title

Σύνθεση και χαρακτηρισμός πορφυρινικών παραγώγων ως φωτοευαισθητοποιητές σε συστήματα αξιοποίησης της ηλιακής ενέργειας.

Author

Νικολάου, Βασίλειος

Thesis advisor

Κουτσολέλος, Αθανάσιος

Reviewer

Δημάδης, Κωνσταντίνος
Μήλιος, Κωνσταντίνος
Τρικαλίτης, Παντελής
Βασιλικογιαννάκης, Γεώργιος
Μητράκη, Άννα
Αγγαρίδης, Παναγιώτης

Abstract

This dissertation describes the preparation of novel porphyrin derivatives and their investigation as photosensitizers in various solar-based applications. The newly synthesized porphyrin entities were either modified with appropriate functional groups or linked with different chromophores, such as fullerene, corrole or BODIPY moieties. In the present thesis, the development of energy/electron transfer systems, light emitting electrochemical cells, supramolecular assemblies and dye-sensitized solar cells based on those porphyrin derivatives is examined. The main synthetic approach used for the successful formation of all the above mentioned porphyrinic dyes, was the azide-alkyne cycloaddition (or “click reaction”), which proved an efficient and facile method in stitching different moieties together. Regarding the energy/electron transfer part, the synthesis, the photo-physical and the electrochemical characterization are described for a series of porphyrin-BODIPY dyads as well as for a click-made porphyrin-corrole compound. Overall, the studies presented in the particular section of the PhD suggest that upon photo-excitation, energy transfer and electron transfer processes occur for the porphyrin-BODIPY dyads and porphyrin-corrole moiety, respectively. Furthermore, click chemistry was utilized for the synthesis of two porphyrin-BODIPY dyads and the first application of such compounds in light-emitting electrochemical cells is reported. The photo-physical and the electrochemical characterization of the novel dyads are presented along with their results in lighting schemes. The developed devices were comprised of unique features that led to remarkable stability and efficiency. DNA modification by porphyrin derivatives is also discussed via three different synthetic approaches. More specifically, two different click reactions (copper-catalyzed and copper-free) and an amide coupling reaction were probed in order to efficiently attach various azide-porphyrins or amine-porphyrins onto a series of oligonucleotides. The developed DNA-multi-porphyrin arrays were assembled in supramolecular structures providing an efficient route for exciton coupling. Hence, an elegant method to create porphyrin wires linked to DNA strands that could be utilized in applications such as bio-nanotechnology. Lastly, a series of porphyrin-fullerene dyads as well as two modified porphyrin derivatives have been prepared and studied as sensitizers in p- and n-type dye-sensitized solar cells, respectively. Concerning the click-made porphyrin-fullerene dyads, the optimal position of a spacer was examined, with respect to the device performance. While for the modified porphyrin derivatives that were prepared for n-type solar cells, the presence of a new electron withdrawing unit between the porphyrin macrocycle and the anchoring group was studied.

Language

English

Subject

BODIPY

Click chemistry

Corrole

Energy/electron transfer

Fullerene

Light emitting electrochemical cells

Solar cells

Supramolecular assemblies

Ηλεκτροχημικές συσκευές εκπομπής φωτός