Field-effect transistor with the water-soluble self-acid-doped polyaniline thin films as semiconductor

UV-Vis spectroscopy and conductivity of the water-soluble self-acid-doped conducting polyanilines, poly(aniline-co-N-propanesulfonic acid aniline) (PAPSAH) and sulfonic acid ring substituted polyaniline (SPAN), in comparison with those of HCl-doped polyaniline, show that the decreases in polaron delocalization and structural order result from the steric hindrance imparted by the sulfonic acid substituent. The field-effect transistors (FETs) are fabricated with the water-soluble self-acid-doped conducting polyanilines: PAPSAH and SPAN films, respectively, as the semiconducting layer. These FETs have ideal source current-drain source voltage characteristics and their field-effect mobilities can reach 2.14 (PAPSAH) and 0.33 cm(2) V-1 s(-1) (SPAN), which are close to those of the amorphous silicon inorganic transistors (0.1-1.0 cm(2) V-1 s(-1)) used extensively at present. These FETs are found to be environmentally more stable than those of other polyaniline FETs. (C) 1998 Elsevier Science S.A. All rights reserved.