Transient photoconductivity in orientedtrans-polyacetylene prepared by the Naarmann-Theophilou method

We present transient-photoconductivity results of oriented trans-polyacetylene prepared by the Naarmann-Theophilou method. In addition to the usual fast-decaying photocurrent peak, we report a large long-lived, temperature-dependent tail not previously seen in other forms of polyacetylene. By comparison of the data to that obtained from high-quality single crystals of polydiacetylene, we conclude that the magnitude of this tail implies higher-quality polyacetylene. The anisotropic behavior for different polarizations of the incident light is presented together with the effect of light intensity, temperature, and external field strength.