IMPLANTED POLYMER JUNCTIONS FROM HIGHLY COMPACTED POLYPYRROLE FILMS

Electrochemical techniques allow the control of the morphology of cond ucting polymers. After synthesis, polypyrrole films grafted on alumini um electrodes can be electrochemically reduced at very low cathodic po tentials, obtaining bulk conductivities of 10(-6) S cm(-1), stable for months. This high stability is attained by means of the closure of th e polymeric entanglement during the cathodic treatment, which hinders oxygen diffusion through the polymer, avoiding self-doping processes. After implantation of alkali ions, polypyrrole-based p-n junctions, st able for several months, are obtained.