Design of porphyrin-polyphenyleneethynylene light harvesting systems

摘要

The design of light harvesting systems based on zinc-porphyrin linked polyphenyleneethynylene systems is demonstrated through two different synthetic procedures. The use of the Sonogashira cross-coupling reaction was found to be problematic in several aspects and it was only possible for one of the synthetic strategies to incorporate a single porphyrin molecule in each polymer chain. The polymer materials were separated into fractions using preparative SEC and subjected to photophysical studies in both the solution and in the solid state. In the solid state light harvesting by the pendent polyphenyleneethynylene and energy transfer to the zinc-porphyrin was found to be high whereas it was low in solution. This observation was confirmed when making electroactive devices. Ⅰ/Ⅴ characteristics were measured on fabricated solar cells of the polymers. Material properties for the native polyphenyleneethynylene were determined using ultra violet photoelectron spectroscopy on thin films and carrier mobility studies were performed using pulse radiolysis time resolved microwave conductivity.