Electron spectroscopic investigation of polymers and glasses

Abstract

X-ray induced photo and Auger electron spectroscopic techniques have been applied to investigate conducting polymers, their blends and some glasses. In the N1s region of the spectra of films containing polypyrrole the peak corresponding to N+ at 402.0 eV is separated from the neutral N. Intensity of the N+ peak can be correlated with electrical conductivity of the films and the spectroscopically derived ratio of F/N+ is close to 4 indicating that one BF4- dopant ion is incorporated for every oxidized nitrogen center. In the spectra of the films of polythiophene and its blends peaks corresponding to S and S+ can not be resolved, but again F/C ratio correlates with the electrical conductivity. On the basis of measured XPS chemical shifts in the binding energies the chemical state of Sn (+2 or +4) incorporated on to the float glasses could not be assigned. Use of the Auger parameter lets one separate relaxation and chemical contributions. The derived true chemical shifts of Sn on float-glasses are larger than those of SnO and/or SnO2 due to the larger ionic environment of the glass matrix.