Ambipolar organic thin film transistors prepared with a one step solution technique

• Zone-casting was used to make oriented blends of organic semiconductors.
• OFETs were made of blends of p-type and n-type material and Parylene C gate dielectric.
• The OFETs presented exhibit ambipolar behavior.
• The parameters of ambipolar OFETs with blended semiconductors are fairly symmetric.

One of the most challenging problems limiting the development of the technology of organic electronics is a lack of simple, solution based, techniques for producing organic thin film transistors (OTFTs) with ambipolar characteristics. In this work, a simple method of manufacturing ambipolar OTFTs, based on a zone-casting technique, is presented. This technique was used to prepare thin and highly oriented films from a combination of the p-type organic semiconductor, TIPS-Pentacene, with one of the two naphthalene bisimide derivatives, both exhibiting electron conductivity. The OTFTs produced with such active layers display ambipolar properties with symmetric characteristics and electron and hole mobility in the best case amounting to: μe = 1.5 × 10−2 and μh = 1.1 × 10−2 cm2 V−1 s−1, respectively.