Robert Jones, R. H. Tredgold, P. Hodge
Jan 14, 1983
Citations
0
Influential Citations
51
Citations
Journal
Thin Solid Films
Abstract
Abstract Protoporphyrin IX dimethyl ester, cobalt mesoporphyrin IX dimethyl ester, and tetra(4-carbomethoxyphenyl)porphyrin form condensed Langmuir films which can be transferred at 20–30 mN m −1 to quartz or aluminized substrates by an unusual Z deposition process. Some preliminary electrical measurements for Al/porphyrin/Au in a conventional sandwich cell arrangement and for Au/porphyrin/Au on quartz in a surface cell arrangement are reported. The capacitance and dark d.c. conductance of monolayers and multilayers on aluminium suggest that films of uniform quality and high dielectric constant have been produced. Protoporphyrin IX dimethyl ester is highly photoconductive in both cell arrangements, with a conductivity anisotropy of 10 4 −10 5 . Its action spectrum corresponds closely to the absorption spectrum of the solid film. The behaviour is compared and contrasted with that of chlorophyll-a and of the cobalt complexes of chlorophyll-a and the mesoporphyrin and is discussed in terms of the film structure which allows close packing of the porphyrin rings.