Impact of Stoichiometry and Fluorine Atoms on the Charge Transport of Perylene-F4TCNQ.

The charge-transport properties of charge-transfer complexes (CTCs) play a key role in the potential applications toward novel optoelectronic devices. We have systematically studied the charge-transport properties of perylene-F4TCNQ CTCs with different stoichiometric ratios by first-principles calculations. Our calculated results showed that 1P1F4 (perylene-F4TCNQ 1:1) exhibits a higher charge-carrier mobility than 3P2F4 (perylene-F4TCNQ 3:2) due to the strong interlayer interactions in 3P2F4. Compared with the perylene-TCNQ CTC, the higher charge-carrier mobility in perylene-F4TCNQ CTC indicates that introducing fluorine atoms can enhance the charge-carrier mobility due to stronger intermolecular interactions. More importantly, the experimental measurements carried out with 1P1F4- and 3P2F4-based field-effect transistors are consistent with the theoretical predictions. Our study reveals that tuning the charge-transport properties in CTCs by controlling the stoichiometry between the donor and acceptor is a promising strategy in accelerating the development of high-performance organic electronic materials.