Theoretical investigations on charge transport properties of tetrabenzo[a,d,j,m]coronene derivatives using different density functional theory functionals (B3LYP, M06-2X, and wB97XD)

Charge transport rate is one of the key parameters determining the performance of organic electronic devices. Based on density functional theory, exchange-correlation functionals which adequately account for non-covalent interactions, such as M06-2X and wB97XD, should significantly improve the accuracy of charge transport rate calculations for large systems with non-covalent interactions. In this work, the B3LYP hybrid functional, the variant hybrid functional M06-2X, and the long-range-corrected wB97XD functional were used to perform geometry optimizations and charge transport rate calculations on 11 variants of tetrabenzo[a,d,j,m]coronene, including tetrabenzo[a,d,j,m]coronene itself and its tetrasubstituted and octa-substituted derivatives. Our results indicate that the molecular geometries of these benzocoronene semiconductors are large quasi-planar conjugated pi systems, and the incorporation of different substituents significantly affects their frontier molecular orbitals. The hole carrier mobility (mu(+)) and electron carrier mobility (mu(-)) of the methoxy-substituted derivatives (TBC(OCH3)(4) and TBC(OCH3)(8)) were relatively low. The results of the tetrabenzo[a,d,j,m] coronene molecules studied were consistent with using the aforementioned M06-2X, wB97XD, and B3LYP methods. We found that the octa-substituted derivatives (TBCF8, TBCCI8, TBC(CH3)(8), and TBC(CN)(8)) could be used as p-type organic semiconductor materials.