Dispersive geminate recombination in a conjugated polymer

Decay of delayed fluorescence (DF) originating from geminate electron-hole pair recombination in a thin film of a conjugated polymer, a ladder-type methyl-substituted poly (para-phenylene) (MeLPPP), has been measured as a function of time at different temperatures. On the time scale of 10(-4)-10(-2) s an algebraic law, DF(t) similar to t(-n), is approached, where n changes from 1.1 at 83 K to about 2.7 at room temperatures. Experimental results are in a good agreement with the developed theoretical model of geminate recombination of charge carriers under the premise that the transport is dispersive. (C) 2001 Elsevier Science B.V. All rights reserved.