ELLIPSOMETRIC STUDIES OF POLYANILINE - EFFECTIVE DIMENSION OF CONDUCTING STATES

A model of fractional-dimensional space is employed to study the measu red ellipsometric spectra of polyaniline with acid doping treatment. A side from some band parameters, the important dimensional properties o f electronic states in the system associated with direct interband tra nsitions can be obtained. The results indicate that as doping density is increased, the effective dimension (D) of electron states in the po lyaniline changes from about 1.5D to near 2.6D, in the same time the p olyaniline shows an insulator-metal transition. A brief discussion abo ut the results is given.