Pentacene transistor encapsulated by poly-para-xylylene behaving as gate dielectric insulator and passivation film

We present pentacene thin-film transistors with poly-para-xylylene gate dielectric and passivation films for plastic electronics. Both the poly-para-xylylene films are formed by dry chemical vapor deposition at room temperature. An organic pentacene channel is fully encapsulated by poly-para-xylylene films, except in the area of electrode connection. Passivation induces little degradation of the organic transistor properties. In addition, a small amount of charge transfer molecules are introduced between the pentacene channel and the metal electrodes to improve device performance. Contact resistance is sufficiently reduced by the employment of the charge transfer molecules, which is analyzed using a transmission-line model.