Conducting polymer ultrathin film shows promising future for gas sensor application due to their high conductivity and excellent doping/dedoping performance. In this work, based on an modified Langmuir-Blodgett film method, ultrathin conducting poly(3,4-ethylene dioxythiophene) (PEDOT) film was fabricated. The PEDOT ultathin film was characterized by UV-Vis absorption spectrum, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) techniques. The results showed small PEDOT grains distributed in polymer LB films after the polymerization of monomer. This ultrathin film exhibited an electrical conductivity about 1.2 Scm^-1, and the conductivity increased and decreased to 16.8 and 0.03 Scm^-1 after doping and dedoping treatment. The interaction or response of films coated QCM to NH₃ have been tested and it has been found that sensitivity of the composite films on QCM showed better sensitivity than bulk material. To the same analyte concentration, it increased with the increasing number of LB layers coated onto QCMS before 80 layers, and then a decrease of sensitivity of QCM was observed after the layer number exceeded 80 layers. The interaction mechanisms between the ultrathin film and analyte vapor were also included.

Date Published: 11 March 2008
PDF: 4 pages
Proc. SPIE 6984, Sixth International Conference on Thin Film Physics and Applications, 69843R (11 March 2008); doi: 10.1117/12.792245

Published in SPIE Proceedings Vol. 6984:
Sixth International Conference on Thin Film Physics and Applications
Wenzhong Shen; Junhao Chu, Editor(s)