Doping effect of charged porphyrin derivative into multilayered conducting polymer heterostructure by self-assembly method

Optical and electrical properties of molecularly doped multilayered heterostructures of conducting polymers, which were prepared by alternative dipping of a substrate into a solution of a negatively charged conducting polymer and a mixed solution of a positively charged conducting polymer and a positively charged porphyrin, have been studied. In spite of the low doping level of the porphyrin, remarkable photocurrent enhancement was observed in the doped multilayered heterostructure. This doping effect was explained in terms of efficient photoinduced charge separation at the interfaces between negatively and positively charged conducting polymers and also at the interface between porphyrin derivative and conducting polymers. The photoconduction was also found to be dependent on the polarization of excitation light.