P-N junction diode formation has been achieved for the first time in a
single polyaniline film, cation doped chemically on one side and anio
n doped by irradiation of ions from dense plasma focus on the other si
de. The diode behaviour is confirmed by I-V characteristics. The resul
ts of ESCA, XRD and SEM for chemical composition, structure and surfac
e morphology, respectively, are also reported for these films.