Performance of Parylene-Packaged Flexible Pentacene Thin-Film Transistors in Saline

A micro-fabricated parylene-packaged flexible pentacene thin film transistor is presented. Different from preceding devices that have been reported, this thin film transistor employs parylene as the substrate, the gate insulator and also the top protection layer. Also, this thin film transistor uses pentacene, an organic semiconductor with high mobility, as the active material. The fresh made thin film transistor shows a hole mobility of 0.022 cm^2/V-s. In spite of initial drops, the transistor's hole mobility stays at 0.001 cm^2/V-s after over 6-month soaking in saline. We can conclude that drifts in mobility from soaking do exist but they saturate to values still of promise In addition, we believe there's plenty of room to improve the parylene packaging such as by using thicker parylene (this work used only 1 µm).