Factors determining polaron mobility in light-emitting diodes

Publisher Website
Google Scholar
Abstract
Mobility of positive polarons in poly(phenylene vinylene), PPV, measured by time of flight methods, rages from approximately 10-3 to 10-7 cm2/Vs at room temperature. The large range indicates that the materials are disordered. Both disorder and polaronic effects contribute to the activation energy for hopping, but in PPV the polaronic effects are less important and to first approximation may be neglected. Comparison of the observed field dependence of mobility for two sets of samples with the results of Monte Carlo simulations leads to the conclusion that the contribution of site energy disorder is predominant in one case, but comparable to that of orientational disorder in the other. We suggest that the most important factor leading to the wide range of mobility values is different distributions of conjugation lengths, resulting from different choices of precursor polymer and conversion protocol.

This publication has 0 references indexed in Scilit: