SENSITIVE THERMOELECTRIC-POWER AND CONDUCTIVITY MEASUREMENTS ON IMPLANTED POLYPARAPHENYLENE THIN-FILMS

A sensitive apparatus for determining the conductivity and thermoelect ric power of conducting polymer films at temperatures between 150 and 450 K is described, Brittle polyparaphenylene films doped by ion impla ntation with either alkali (caesium, sodium) or halogen (iodine) ions are studied by this method, Analysis of the temperature dependence of both conductivity and thermopower shows that the doping process of thi s conjugated polymer is efficient only when low parameters of implanta tion are selected and appears around room temperature, At higher tempe ratures the thermopower exhibits an anomalous evolution that we attrib ute to oxygen migration. (C) 1997 John Wiley & Sons, Ltd.