Theoretical evaluation of charge transport properties and mobility of tetraphenyldipyranylidene derivatives in organic field-effect transistors

Density functional theory calculations were performed to calculate the structural, electronic, physical, and hole/ electron charge transport properties of three possible pathways of Tetraphenyldipyranylidene (DPPh) derivatives including electron-acceptor atoms and electron-donor groups as the organic semiconductors in organic field-effect transistors (OFETs). Additionally, the reduced density gradient-based non-covalent interaction (RDG-NCI) analysis was performed to investigate the presence of non-covalent intermolecular interactions. The results of electronic and physical properties show that all compounds are stable in environmental conditions and intermolecular interactions between the three possible dimers of each compound are different. The maximum mobility (mu(max)) and anisotropic mobility (mu phi(max)) of the hole (0.16 cm2 V-1 s-1) is greater than that of the electron in DPPh, which is in good agreement with the experiment. The mobility of the hole decreases by introducing the electron-acceptor atoms and electron-donor groups. However, mu(max) and mu phi(max) values of the electron in the case of DPPh derivatives increase including C(CH3)3, Br, OCH3, CH3, Cl, and -OCH2CH3, respectively. According to different analyses, DPPh-CH3, DPPh-C(CH3)3, DPPh-Br, and DPPh-Cl semiconductors are proposed as the preferred candidates for use in the OFET devices.