IMPLANTED POLYMER JUNCTIONS OBTAINED WITH ELECTROGENERATED POLYTHIOPHENE FILMS

Using polythiophene films (similar to 5 mu m thick) electrogenerated b y trapezoidal waves of potential, then partially reduced, we realised metal-polythiophene contacts on the one hand. The electrical character istics of a steel/polythiophene/gold sandwich structure are presented. We consider that the rectifying contact takes place between steel and p-type polythiophene, On the other hand, we showed that p-type polyth iophene could be compensated after an implantation of alkali ions (Cs or Na+) in order to lead to the realisation of PN junctions. We parti cularly prove that the use of Na+ ions results in junctions yielding c urrents which are higher than with Cs+ ions. Current-voltage and capac itance-voltage characteristics have been presented so as to show that the junction effect is due to the efficiency of the doping by ionic im plantation. These electrical measurements seem to be stable after seve ral weeks in air.