Electric field and temperature dependence of the hole mobility in a bis-fluorene cored dendrimer

Time-of-flight mobility measurements on a first generation, bis(fluorene)-cored dendrimer are reported. A charge generation layer was used enabling measurements to be performed on spin-coated films, comparable to those used in devices such as organic light-emitting diodes. The results are compared with spin-coated polyfluorene films. The temperature and electric field dependence of the mobility of the dendrimer was studied and found to be in excellent agreement with the Gaussian disorder model, with an energetic disorder parameter, a, of 74 meV and a positional disorder parameter, Sigma, of 2.6. (c) 2007 Elsevier B.V. All rights reserved.