Polypyrrole (PPY) nanofilms were synthesized by a one-step deposition/polymerization process in a vacuum chamber under ultraviolet photon irradiation. To realize the synthesis of PPY films, the authors measured the current through. a conducting polymer connected by two electrodes. The nanofilms were characterized by atomic force microscopy and Fourier-transform infrared spectroscopy. A possible mechanism is proposed for the formation of the PPY nanostructure during the photopolymerization. (c) 2007 American Vacuum Society.