Structural effects of core-modified porphyrins in dye-sensitized solar cells

A series of core-modified porphyrins with different meso aryl groups (R₁), anchoring groups (R₂), and core atoms (X) were studied as light-harvesting sensitizers for dye-sensitized solar cells (DSSCs). DSSCs were fabricated using these porphyrins as well as TiO₂ nanoparticles with a particle diameter of around 25 nm. A dense layer of TiO₂ was deposited as an interfacial layer on fluorine-doped tin dioxide (FTO) substrates. A TiO₂ nanocrystalline film was then deposited on the dense layer by spin coating. The comparison of DSSC performance from different core-modified porphyrins was studied. The UV-vis absorption spectroscopy of porphyrin films attached on TiO₂ and porphyrin solutions were also measured. The results indicated that both anchoring and meso aryl groups impacted on cell performance. The cell efficiency was correlated to the absorption of porphyrin films attached on TiO₂ at the Soret band.