Merocyanine dye-sensitized photoconductivity of polymer composites based on heterometallic copper/iron complexes

The electric and photoconductive properties of films of polymer composites containing heterometallic complexes [Cu(phen)₂Fe(CN)₅NO]· 2H₂O or [Cu(phen)₂Br]₂[Fe(CN) ₅NO]DMF (where phen is 1,10-phenanthroline and DMF is dimethylformamide) and a merocyanine dye were studied. The photocurrent is greater for the bromide complex and increases upon introduction of a merocyanine dye into the composites. The photocurrent also increases upon the application of an external magnetic field and saturates in fields of <1 kOe. It is assumed that the sensitization of photoconductivity by the merocyanine dye is due to photogeneration of triplet charge pairs from dye molecules and transport of nonequilibrium charge carriers in and between the particles of the complexes, rather than to an increase in the absorbance.