First-Principles Study On The Charge Transport Properties Of Organic Polymorphs

Organic transport materials have been attracted a deal of attention for use in organic field-effect transistors (OFETs), solar cells, and organic light-emitting diodes (OLEDs), which possess great advantages such as low cost, easy fabrication, and mechanical flexibility. Organic transport materials can be divided into organic small molecules, polymers, and organic metal complexes. The factors that determine the charge transport properties of different kinds of materials are distinct due to the different structures. For example, the intermolecularπ-πstacking interaction plays the key role in the organic small molecules; while for organic metal complexes, the metal-metal interaction can not be ignored. On the other hand, there exists polymorphs in the organic molecular crystals, and thus supply the models to investigate the influences of different interactions on the transport properties.J?kle et al. synthesized a series of organocopper complexes, through Cu-π, Cu-S, perfluoroarene-arene, and cuprophilic interactions. Some of these complexes possess fascinating luminescent properties, and the transport properties are interesting due to the exist of cuprophilic interaction. Wang and co-workers designed and synthesized a series of organic polymorphic luminescent crystals constructed by 3(5)-(9-anthryl)pyrazole (ANP), and their optical properties are different resulting from their unique interactions based on hydrogen bonding andπ...πstacking interactions.We carried out density functional theory and band model to investigate the charge transport properties based on different kinds of organic molecular crystals with different intermolecular interactions systemmetically. It is fundamental and also important for designing new organic transport materials.