The role of charge-transfer integral in determining and engineering the carrier mobilities of 9,10-di(2-naphthyl)anthracene compounds

The charge transporting properties of t-butylated 9,10-di(2-naphthyl)anthracene (ADN) compounds have been investigated experimentally and computationally in relation to their molecular structures. The ADN compounds are found to be ambipolar with both electron and hole mobilities in the range of 1-4 x 10(-7) cm(2) V-1 s(-1) (electric field 0.5-0.8 MV/cm). As the degree of t-butylation increases, the carrier mobility decreases progressively. The mobility reduction was examined by Marcus theory of reorganization energies. All ADN compounds possess similar reorganization energies of similar to 0.3 eV. The reduction of carrier mobilities with increasing t-butylation can be attributed to a decrease in the charge-transfer integral or the wavefunction overlap. (c) 2006 Elsevier B.V. All rights reserved.