Effects of crystal structures and intermolecular interactions on charge transport properties of organic semiconductors

摘要

In this study, the effects of the packing configuration and intermolecular interaction on the transport properties are investigated based on density functional theory. Molecular design from the standpoint of a quantum-chemical view is helpful to engender favorable molecular packing motifs. The transfer integral along the orientation with pi-pi overlap is much larger than other directions without pi-pi overlap, and the mobility along this orientation is higher than that along other directions. The intermolecular interaction analyses demonstrate that hydrogen bonds play a crucial role with strong electrostatic interactions in charge transfer. There will be a synergistic relationship when the pi-pi stacking and intermolecular interaction coexist in the same direction. It turns out that intermolecular interactions are responsible for charge transport, while pi-pi stacking interactions dominate donor-acceptor transport. Incorporating the understanding of the molecular packing motifs and intermolecular interactions into the design of organic semiconductors can assist in the development of novel materials.