Characterization of intrinsic hysteresis of pentacene-based organic thin-film transistor through in-situ electrical measurement

The intrinsic hysteresis behavior of a pentacene-based organic thin-film transistor (OTFT) was characterized through home-designed in-situ electrical measurement. The device can measure an intrinsic hysteresis after the device's fabrication under vacuum. In addition, the same hysteresis and electrical properties were observed when venting a nitrogen gas. Compared with the measurement condition of vacuum or nitrogen gas, exposure to the ambient air resulted in a severe hysteresis. This is because both the acceptor-like traps at the organic/dielectric interface and donor-like traps in the transport channel contributed to the effect of hysteresis in the OTFT. When the chamber was vacuumed out again, a significantly reduced hysteresis was obtained; almost the same as measured the first time. These results indicate that extrinsic hysteresis from oxygen and water is reversible.