Effects of structural disorder and temperature on the distribution of exciton binding energy in poly(phenylene vinylene) films

Luminescence quenching experiments on oriented and drop-cast poly(phenylene vinylene) (PPV), films identify the excitons in these polymer films as Wannier-Mott excitons. The data are interpreted in terms of a distribution of exciton binding energies (E-b). We find that the width of this distribution is well correlated with the degree of structural disorder. The relatively small mean E-b, approximately 60 mev, results in field-induced exciton disociations that limits the quantum efficiency obtained from polymer-based light emitting diodes (PLEDs) which typically are operated at applied fields of 10(6) V/cm or greater where the field-induced exciton disociations is significant. We present data and analysis that support these conclusions, as well as a discussion on the implications of our findings on polymer-based display technology. (C) 2003 Elsevier Science B.V. All rights reserved.