The impact of molecular stacking interactions on the electronic structure and charge transport properties in distyrylbenzene (DSB-) based D-A complexes: a theoretical study

The molecular aggregation structure of three D-A cocrystal complexes based on substituted distyrylbenzenes (DSB) was studied by density functional theory calculations. The influence of molecular stacking on molecular interactions, frontier molecular orbitals, charge transport and photophysical properties has been investigated in depth, by comparison of D1-A1, D2-A2 and D2-A2' pairs with different substituents in D and A monomers. Our results provide not only a better understanding of the relationship of the D-A configuration and electrical/optical properties, but also the theoretical prediction of novel organic semiconductor materials for the mixed-stack D-A charge-transfer crystal. In particular, the charge-transfer complexes of D1-A1 have been demonstrated as a good ambipolar material, while the complexes of D2-A2 and D2-A2' should conduct as better n-type organic semiconductor materials.