Theoretical Study of Electronic Structures and Charge Transport Properties of 9,10-Bis((E)-2-(pyrid-n-yl) vinyl) (n=2,3,4) Anthracene

Charge carrier mobility is one of the most significant properties for organic semiconductors. In this work, the electronic structures and charge transport properties of 9,10-bis((E)-2-(pyrid-n-yl)vinyl) (n=2, 3, 4) anthracene (BP2VA, BP3VA and BP4VA) were investigated via the analysis of the molecular geometry, the reorganization energy, the frontier orbital and density of state, as well as the electronic coupling and the charge mobility. The results indicated that the linkage between 9,10-divinyl anthracene unit and pyridine (ortho-, meta- and para-) influenced not only the intra-molecular conformation (i.e., the reorganization energies), but also the intermolecular interaction (i.e., transfer integrals), and finally the charge mobility of the molecules. It is also found that: (1) The calculated charge mobilties of holes are dozens of times higher than those of electrons for the three molecules. (2) The charge mobilities of hole and electron of the three molecules display the trend: μ_BP4VA>μ_BP2VA>μ_BP3VA, and the hole mobility of BP4VA is as high as ~1 cm²/(V·s). The linkage (ortho-, meta- and para-) between 9,10-divinyl anthracene unit and pyridine significantly influences the charge carrier mobilities, and shows the trend as μ_BP4VA>μ_BP2VA>μ_BP3VA.