Transient photocurrents and steady-state conductivities in surface-doped polyanilines

Steady-state dark currents and transient photocurrents were measured in pol yaniline (PANI) and poly(o-methoxyaniline) (FOMA), asymmetrically protonate d on one surface with various acids. In both polymers a rectification behav iour was found, indicating that the doped surfaces of the samples act as co ntacts injecting holes into the undoped bulk. Well defined transit times we re measured in POMA: ambient-temperature hole mobility, estimated from the experiments, amounts to ca. 3x10(-4) cm(2)/Vs. Shapes of transient photocur rent-time dependences in PANI were featureless and decaying monoexponential ly to their steady-state values, with the time constants of the order of 10 (-2)s.