One of the most interesting questions in modern transport theory has been and still is the following: What is the influence of dimensionality (including fractal) on the carrier and exciton dynamics and decay kinetics in quasiordered and disordered systems. An enormous amount of theoretical work has been done in this field, extended now to include direct computer simulations. Experimental data have been more difficult to find and are consequently sparse and not always convincing. Certain types of organic compounds and, in particular polydiacetylenes, constitute unique classes of nearly one-dimensional systems. Studies including photoconductive decays have been extended to include picosecond luminescence decay on PDA-1OH [poly(diacetylene-1-hydroxy-hexadyine-diol)], a continuous highly oriented fibrous polymer. The decay laws are compared with exact results in dimensionalities d=1 and near 1. The present data together with the recent work on doped tetramethylammonium manganese trichloride may be evidence for the first time of one-dimensional exciton motion.

• Received 17 October 1986

DOI:https://doi.org/10.1103/PhysRevB.35.8103