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

Optical and electrical properties of molecularly doped multilayered heteros tructures of conducting polymers, which were prepared by alternative dippin g of a substrate into a solution of a negatively charged conducting polymer and a mixed solution of a positively charged conducting polymer and a posi tively charged porphyrin, have been studied. In spite of the low doping lev el of the porphyrin, remarkable photocurrent enhancement was observed in th e doped multilayered heterostructure. This doping effect was explained in t erms of efficient photoinduced charge separation at the interfaces between negatively and positively charged conducting polymers and also at the inter face between porphyrin derivative and conducting polymers. The photoconduct ion was also found to be dependent on the polarization of excitation light. (C) 1999 American Institute of Physics. [S0021-8979(99)04403-5].