The effect of electric field on the bimolecular recombination rate in a one-dimensional polymer single crystal

Abstract

This work presents results which demonstrate that, for a one-dimensional semi-conducting system, an applied electric field can affect the rate at which photocreated carriers bimolecularly recombine. Such an effect would not be expected in three-dimensional materials. The effect in the one-dimensional single crystal polydiacetylenes has led to previous workers making errors of interpretation of their observations. This present work seeks to correct these, and demonstrate that all observations are consistent with the view that carriers move with a saturated drift velocity, at around the velocity of sound, characteristic of the motion of a solitary wave acoustic polaron in one dimension. Furthermore, the field dependence of the bimolecular recombination rate is seen to be a direct consequence of the Onsager geminate recombination mechanism, as modified to account for the one dimensionality of the semiconductor.