A simulation approach for improvement of contact resistance in organic field-effect transistors by modification of the contact interface using an organic buffer layer
摘要
Contact resistance has remained a major performance obstacle in organic field-effect transistors (OFETs). This article shows a simulation-based effective approach to evaluate and reduce contact resistance by modifying contact properties using a pentacene organic semiconductor buffer layer. The source and drain consist of copper contacts on a high-mobility organic semiconductor (S-DNTT10); hafnium dioxide (HfO2) is acting as a dielectric and aluminum (Al) as gate contact in a top-contact OFET arrangement. Results show reduction in contact resistance to 64.29 Ω.cm using Cu/pentacene electrode contacts compared to 8357 Ω.cm for a Cu-only contact. The transmission line method was used to evaluate and analyze contact resistance. The extracted electrical performance parameters showed an excellent on–off current ratio of ~ 109, improved threshold voltage of 1.32 V, and significant improvement in hole field-effect mobility and subthreshold swing (SS). Thus, the Cu/pentacene electrode contact is a better alternative for contact resistance reduction in OFETs for biomedical and display applications.