Theoretical Investigations on Charge-Transfer Properties of Novel High Mobility n-Channel Organic Semiconductors – Diazapentacene Derivatives

The charge-transfer properties of three diazapentacene derivatives, including 5,7,12,14-tetrachloro-6,13-diazapentacene (TCDAP), 5,7,12,14-tetrachloro-6,13-diaza-6,13-dihydropentacene (TCDAHP), and 5,7,12,14-tetrafluoro-6,13-diazapentacene (TFDAP), have been studied using density functional theory. The performance of five pure GGA and seven hybrid GGA functionals and G3MP2B3 method on the reorganization energy (λ) and mobility (μ) predictions of TCDAP has been examined. Both the B3LYP functional and the G3MP2B3 method give reliable predictions for the λ value. Using the reorganization energy at the G3MP2B3 level together with the transfer integral by BHandH, BHandHLYP, and M06-2X functionals yields electron mobilities of 3.44, 3.32, and 3.29 cm2 V–1 S–1 for TCDAP, respectively, which come fortuitously close to the experimental value of 3.39 cm2 V–1 S–1. Other density functionals also give mobility predictions in agreement with the experimental value to a factor of ∼2. The TCDAHP, a −NH derivative of TCDAP...