Other Thermal and Environmental Stability Test Methods

3 Other Thermal and Environmental Stability Test Methods 

11-27 a) Relative conductivity decay in highly FeClj-doped poly(3-octylthio-phene) for film thicknesses 15 and 90 pm with initial room temperature conductivities of 1.1 and 2.4 S/cm, respectively, b) Conductivity decay in 30 pm thick poly(3-octylthiophene) films at various doping levels. The temperature was cycled between 25 C and 70 C at a relative humidity level of (85 5) %. After Reference [208b], reproduced with permission. 

X-Ray photoelectron spectroscopy (XPS) or ESCA is another routine analytical technique whose application to CPs is best illustrated by examples. Wide-spectrum XPS is a simple tool for elemental analysis, useful, e.g., to see the presence of an atom belonging to a particular dopant to verify doping. Higher resolution (core-level) XPS is typically useful for determining oxidation states of a central heteroatom, e.g. the N-atom in poly(aromatic amines), hence elucidating the redox state of the polymer or at least of the central heteroatom. Finally, valence-level spectra, at very low energies, have been said to be usable for estimation of density of states, although their accuracy is questionable. 

11-30 N XPS core levels spectra of P(ANi) (85 cycles). The finer lines are the fits to the data. After Reference [257], reproduced with permission. 

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