A novel n-type organic semiconductor comprising a 1,5-naphthyridine-2,6-dione unit

Abstract

The first examples of 1,5-naphthyridine-2,6-dione (NTD)-based n-type small molecules, NTDT-DCV and NTDP-DCV with an electron-withdrawing dicyanovinyl terminal unit and different aromatic bridging groups (thiophene and benzene, respectively), were synthesized and characterized. Two different bridging rings were incorporated to explore the structure–property relationship as well as to precisely control the electrical properties. Among them, NTDT-DCV exhibited a higher maximum electron mobility of 0.14 cm² V⁻¹ s⁻¹ in organic thin-film transistors (OFETs), attributed to the planar structure, low reorganization energy, and well-connected smooth surface thin-films. To further demonstrate the n-type properties of NTDT-DCV, we have fabricated a p-type OFET device with overlaid NTDT-DCV nanopatches. While the pristine OFET with a p-type NTDT semiconductor showed a hole mobility of 1.29 cm² V⁻¹ s⁻¹, that with an overlaid NTDT-DCV nanopatch showed an increased hole mobility of 2.41 cm² V⁻¹ s⁻¹, ascribed to the appropriate energy level offset and efficient intermolecular charge-transfer doping interaction into the overlaid nanopatch.