2-MM waveband EPR study of organic polymer semiconductors

Summary form only given. Organic polymer semiconductors (OPS) in which the charge transfer is realized by nonlinear excitations, solitons and polarons, have been studied extensively in recent years by various methods, including EPR. Up today OPS were studied in a comparatively low frequency (/spl nu/ /spl les/ 10 GHz) range EPR,where a complete overlapping of spectral components of most organic radicals with a weak spin-orbit coupling and cross processes between the individual spin-packets are most possible. The sensitivity and informativity of the method increase considerably at 2-mm waveband EPR allowing one to obtain an additional information on various properties of OPS, including dynamics of charge carriers and the mechanism of charge transfer in them [1]. The aspects of the investigation of various OPS by using the high spectral resolution 2-mm waveband EPR technique accompanied by the methods of steady-state saturation of spin-packets, spin label and probe as well as saturation transfer are discussed in the report. It reviews the original 2-mm EPR data concerned with a nature,relaxation and dynamics of paramagnetic centers in neutral and differently doped polyacetylene, polyaniline, poly(p-phenylene), polythiophene, polypyrrole and poly(tetrathiafulvalene) semiconductors. The mechanisms of charge transfer in these polymers are discussed.as well.