PECCS Measurements in Organic FETs

Organic field-effect transistors (OFETs) have been extensively investigated for display and many other electronic applications, since they are expected to promote advances in plastic or glass electronics based on low cost and flexibility. Whether the type of organic semiconductor channels are small molecule-based or polymer-based, the performance and stability of OFETs strongly depends on the nature and density of charge traps present at the channel/dielectric interface and in the thin-film channel itself near the interface [1–3]. Therefore the characterization of these traps is critical. We here introduce PECCS-based DOS measurements on p-channel [4] and n-channel [5] small molecule (thermally evaporated pentacene)-based FETs with differently prepared channel/dielectric interface, so that we can display detailed mid-gap states in the various channel/dielectric interfaces of FET devices. In another section of, [6] we also included some detailed PECCS studies on polymer-based OFETs where their channels were composed of polymers such as P3HT etc., since the photo-induced current in polymer-based OFETs behave different from small-molecule OFETs.