Charge Transport in Molecularly Doped Polymers: Tests of the Correlated Disorder Model

Abstract

The correlated disorder model (CDM) has been proposed as a theory of charge transport in molecularly doped polymers (MDPs). Recently a test of the CDM was proposed: it was predicted that the dipolar disorder energy can be obtained from the slope of the log of the mobility versus square root of the electric field (the Poole-Frenkel or PF slope). We find that the dipolar disorder energy obtained from the experimental PF slopes are almost always larger than the theoretical predictions, especially for MDPs made from dopants with low dipole moments. In addition, the theory relates the dipolar disorder energy to the temperature T0 at which the electric field dependence of the mobility vanishes. We find that the observed T0 does appear to increase as the dipolar disorder increases but is in quantitative agreement (within 25 K) with the theoretical predictions for only a limited set of the measurements. We conclude that it appears that the CDM needs further development to be consistent with charge transport in or...