PHOTOELECTROCHEMICAL BEHAVIOR OF POLY-3-METHYLTHIOPHENE

Photoelectrochemical behavior of poly-3-methylthiophene films on a pla tinum support was investigated in acetonitrilic solutions. At negative potentials, a cathodic photocurrent was exhibited by the electrode, a nd the magnitude increased when the electrode was exposed to light at those potentials. Such a photoactivation phenomenon, as well as the ex perimentally observed above-linear dependence of the photocurrent magn itude on the light intensity, were attributed to photoelectrochemical reduction (undoping) of the polymer itself, which gives rise to an inc rease in the width of a space-charge region where the photocurrent gen eration occurs. The regularities observed suggest that this region is localized near the metal/polymer interface.