Charge relaxation in dispersive materials is often described in terms of the stretched
exponential function (Kohlrausch law). The process can be explained using a "hopping"
model which in principle, also applies to charge transport such as current conduction.
This work analyzed reported transient photoconductivity data on functionalized pentacene
single crystals using a geometric hopping model developed by B. Sturman et al and
extracted values (or range of values) on the materials parameters relevant to charge
relaxation as well as charge transport. Using the correlated disorder model (CDM), we
estimated values of the carrier mobility for the pentacene samples. From these results, we
observed the following: i) the transport site density appeared to be of the same order of
magnitude as the carrier density; ii) it was possible to extract lower bound values on the
materials parameters linked to the transport process; and iii) by matching the simulated
charge decay to the transient photoconductivity data, we were able to refine estimates on
the materials parameters. The data also allowed us to simulate the stretched exponential
decay. Our observations suggested that the stretching index and the carrier mobility were
related. Physically, such interdependence would allow one to demarcate between
localized molecular interactions and distant coulomb interactions.