Temperature dependence of the charge injection in poly-dialkoxy-p-phenylene vinylene

The injection of holes from a Ag electrode into poly-dialkoxy-p-phenylene vinylene is investigated by measuring the current-voltage characteristics as a function of temperature. For this model system, the hole injection is hindered by a contact energy barrier of about 1.0 eV. The observed temperature dependence of the injection-limited current does not agree with the predictions of classical injection models. A recent model, in which the spread in the charge transporting site energy due to disorder is taken into account, consistently describes the measured field and temperature dependence of the injection process. (C) 2001 American Institute of Physics.