Control of interfacial charges of organic semiconductor by a surface polarized layer for high noise-margin inverters with full-swing capability

We present the control mechanism for interfacial charges in an organic field-effect transistor (OFET) by the introduction of a surface polarized layer (SPL), interfaced with a p-type organic semiconductor (p-OS), which generates a transverse dipolar field. The concept of such SPL enables to develop a high noise-margin full-swing inverter of the p-OS, pentacene, on a single substrate. The transverse dipolar field of the SPL of a fluorinated polymer, placed between the p-OS and a gate insulator, plays an essential role in the accumulation of holes at the interface due to the surface dipoles of the fluorinated polymer. Owing to the interfacial holes, the drain current of the p-type OFET becomes to saturate at zero gate voltage and its magnitude lies between the on-current and off-current of a conventional OFET with no SPL. This allows directly the high noise-margin and the full-swing capability of an organic inverter based on the p-OS material.