Characterization of Optical and Charge Transport Properties of TCNQ-based Organic Field Effect Transistors

Y. Chung, S. Melis, X. Zhang, P. Barbara, E. Van Keuren
Georgetown University,
United States

Keywords: charge transfer crystals, organic field effect transistors, evaporative self assembly


Charge transfer cocrystals have interesting applications in the field of organic electronics due to their unique optical and electronic properties. Controlled evaporative self-assembly (CESA) is a technique that produces long, ordered ribbons of material on a substrate from an evaporating solvent. Charge transfer cocrystals were successfully grown using this method to form a neat arrangement of ribbons that were readily integrated with metal electrodes to create organic field-effect (OFET) transistors for electronic measurements. Temperature dependent measurements of the mobility in devices with phenothiazine and 7,7’,8,8’ tetracyanoquinodimethane (PTZ-TCNQ) as the semiconductor indicated a hopping mechanism for the charge transport, which was predominantly n-type conduction. This data could be explained well using a super-exchange model. Additionally, the CESA method has been applied to fabricate OFET transistors using other combinations of charge transfer materials, such as phenoxazine and TCNQ. We compare these optical and electronic properties of these two devices.