Two-dimensional organic single-crystalline p-n junctions for ambipolar field transistors

Abstract

Two-dimensional single-crystalline p-n junctions of organic semiconductors (pn-2DCOSs) show great potential in organic logic circuits due to their single crystal nature and excellent ambipolar charge transport. However, there are only few reports on pn-2DCOSs because it is difficult to obtain such highly ordered structure in p-n junction. Herein, a novel and effective solution processing method of secondary transfer technology based on the facile drop casting is used to fabricate devices of pn-2DCOSs based on C8-BTBT (p-type) and TFT-CN (n-type) successfully. The high-performance ambipolar field transistors based on such ultrathin pn-2DCOSs with several molecular layers thickness show well-balanced ambipolar charge transport behaviors with hole mobility as high as 0.43 cm2 V−1 s−1 and electron mobility up to 0.11 cm2 V−1 s−1, respectively. This work is essential for studying the intrinsic properties of organic p-n junctions and achieving high performance in organic complementary circuits.