Semiconduction in charge-transfer complexes

Electrical conductivities, electron spin resonance spectra, electronic spectra, and Seebeck coefficients of solid charge-transfer complexes of benzidine–iodine, p-phenylenediamine–iodine, and phenothiazine–iodine as well as two antimony chloride complexes of phenothiazine have been studied. The phenothiazine–I 2 system shows change in sign of the majority charge carriers with the donor–acceptor ratio. The effect of ambient gases on the conductivities of a few donors, acceptors, and their complexes in the solid state have been examined. Seebeck coefficient measurements show that the conduction in TCNQ salts takes place by a hopping mechanism.