Abstract
With the goal to tune charge transport and electronic properties of 4,6-di(thiophen-2-yl)pyrimidine (DTP) structure, seven novel V-shaped organic semiconductor compounds were designed by nitrogen doping, oligocenes pi -bridge incorporations and push-pull strategy. Primarily, 4,6-bis-thiazol-2-yl-pyrimidine (1) was designed by nitrogen atoms doping in DTP. Then push-pull system named 1DA was designed by substituting -N(CH3)(2) at R-1 and R-2, while -CF3 at R-3 and R-4 positions of 1. Moreover, various semiconducting materials (2DA-6DA) with tuned properties were designed from 1DA by fusing benzene, naphthalene, anthracene, tetracene and pentacene at both ends. The density functional theory (DFT) and time-dependent DFT were adopted for optimizing the ground and excited state structures, correspondingly. We investigated frontier molecular orbitals, photo-stability, electron injection, electron affinity (EA), ionization energies (IE) and reorganization energies. The push-pull and pi -bridge elongation strategies ominously raise EA while diminish IE values, which may lead to decrease the electron and hole injection obstruction. Besides, donors-acceptors and oligocenes at both ends meaningfully drop the electron reorganization energy values as compared to normally used n-type material, i.e., tris(8-hydroxyquinolinato)aluminium (mer-Alq3). These results revealed that newly designed materials 4DA-6DA would be proficient to be used in n-type semiconductor devices.