Phenoxazine dyes in solid-state dye-sensitized solar cells

Several structural modifications have been made to a sensitizer dye based on the phenoxazine core, which was tested in a solid-state dye-sensitized solar cell configuration based on the hole transporting material 2,2',7,7',-tetrakis(N,N-di-p-methoxyphenyl-amine)-9,9',-spirofluorene. Light-to-power conversion efficiencies between 2.5% and 4.1% are reported. The difference in device performance is significantly related to the variations of dye mol. structure, with dye mols. having surface protecting alkoxy-groups yielding better solar cell devices. The phenoxazine dyes were characterized by their light harvesting capabilities and electronic properties such as electron recombination lifetime and chem. dipole moment.