Charge transport properties of co-evaporated organic–inorganic thin film charge transfer complexes: effects of intermolecular interactions

Abstract

Novel charge transport properties distinguished from their parental materials are intriguing features of charge transfer complexes (CTCs). In this work, co-evaporated molybdenum(VI)oxide and sexithiophene (MoO₃ : 6T) CTC thin film is prepared and its electron and hole transport properties are studied. While the MoO₃ : 6T CTC material shows both electron and hole transport, detailed changes in molecular orbital hybridization are further studied under an external stimulus. Using a simple rubbing process, the intermolecular interaction of the CTC material can be tuned such that changes in optical properties, vibrational modes, chemical states and electronic structures are observed. These changes in properties and charge transport behaviors enable us to understand the influences of CTC frontier molecular orbitals (FMOs) and their degree of coupling on the charge transport properties. This work provides insight into the understanding of the intermolecular interactions and their influence on the charge transport properties of thin film CTCs.