Delay photoconductivity of emeraldine base films

Delay pulse photoconductivity of polyaniline (PANI) films in the form of emeraldine base (EB) has been investigated in the temperature range 120–300 K. Single pulses of the YAG:Nd3+ laser (the second harmonic) with 20 ns pulse duration were used as an eg xcitation source. It was found that the intensity and form of photoconductivity relaxation curves are dependent on the sample temperature. Experimental data were approximated by three functions: F1 ∼ exp[-(t/τ)β], F2∼ exp(-t/τ) and F3 ∼ t−n. The best fit to the experimental data by F1 and F3 functions suggests that the process of the conducting state relaxation in photoexcited conducting polymer is closely connected with the motion of electrons in a disordered medium with traps.