ELECTRON-TRANSPORT IN A MOLECULARLY DOPED POLYMER

Electron mobilities have been measured in ylphenyl)-6-phenyl-4-(dicyan omethylidene)thiopyran (PTS) doped poly(styrene) (PS) over a range of fields, temperatures, and PTS concentrations. The results are describe d by a formalism based on disorder, due to Bassler and coworkers. The key parameter of the formalism is the energy width of the hopping site s. For PTS-doped PS, the width is approximately 0.129 eV and independe nt of the PTS concentration. The width is described by a model based o n dipolar disorder. The model assumes the width is determined by a dip olar component due to the PTS dopant molecule and a van der Waals comp onent. Agreement with experiment requires that the van der Waals compo nent be dependent on the PTS concentration, increasing with increasing PTS dilution. (C) 1996 John Wiley & Sons, Inc.