Contact resistance of dibenzotetrathiafulvalene-based organic transistors with metal and organic electrodes

Thin-film transistors of dibenzotetrathiafulvalene (DBTTF) are investigated by changing the source and drain (S/D) electrode materials. Not only the mobility but also the contact resistance, estimated from the transfer line method, changes depending on the metal work functions. Nonetheless, S/D electrodes made of a metallic organic charge-transfer salt, (tetrathiafulvalene) (tetracyanoquinodimethane) [(TTF)(TCNQ)] exhibits much smaller contact resistance, which is attributed to small potential shift on the organic/organic interface compared with the organic/metal interface. A thin film of (DBTTF)(TCNQ) works as an active layer of air-stable n-channel organic transistors when (TTF)(TCNQ) is used as the S/D electrodes. (c) 2008 American Institute of Physics.