- The differential approach is based on the determination of dimensionless differential slope, for instance, of current-voltage characteristics (IVC), I=f(V). This slope (a) is given by formula alpha=d(lgI)/d(lgV). With such definition the ranges of constancy of the a(V) dependency correspond to the part of IVC characterized by the power behaviour (I similar to V-alpha). The differential slope of alpha(V) dependency gamma = d(lg alpha)/dlgV determines the exponent behaviour of curve (I similar to exp {eV(y)/kT}). Processing by the differential approach of the investigated theoretical or experimental characteristics permits us to determine the peculiarity of charge flow mechanisms, temperature behaviour of conductivity, etc. The theoretical base and some applications of differential approach to the investigation of the current-voltage, temperature and degradation characteristics of the polyaniline and poly(p- phenilenevinilene) based structures have been shown. (c) 2005 Elsevier B.V. All rights reserved
