Superlocalization of the electronic wave functions in conductive polymer blends at concentrations near the percolation threshold

摘要: The ability to solution-process polyaniline (PANI) in the protonated conducting form through use of surfactant counterions has enabled fabrication conductive polymer blends with a percolation threshold at volume fraction near 1%. Electron micrographs PANI complexed camphorsulfonic acid (CSA) poly(methyl methacrylate) show tenuous interconnected network; for concentration PANI-CSA threshold, network is self-similar. Digital analysis shows that thin two-dimensional ``slices`` networks are fractal, area (S) varying as S {alpha} r{sup D}, where D < 2 concentrations below 4%. Near they find {approximately} 1.5, implying fractal dimensionality three dimensions ca. 2.5. electrical conductivity these follows Mott-Deutscher model variable-range hopping on network, {sigma}(T) exp[{minus}(T{sub 0}/T){sup {gamma}}]. They {gamma} increases from = 1/4 pure (indicting among exponentially localized states) 2/3 reduced indicating superlocalized states structure limit Coulomb interaction between electron and holemore » dominates intersite hopping.« less