Heptacene: Synthesis and Its Hole‐Transfer Property in Stable Thin Films
Takaaki Miyazaki, Motonori Watanabe, Toshinori Matsushima, Ching‐Ting Chien, Chihaya Adachi, Shih‐Sheng Sun, Hiroyuki Furuta, Tahsin J. Chow
Abstract
Abstract Heptacene ( 1 ) has been produced via a monoketone precursor, 2 , which was prepared from 1,2,4,5‐tetrabromobenzene in nine steps in a total yield of 10 %. Compound 2 was converted to 1 quantitatively by heating at 202 °C. Heptacene exhibited high thermal stability in the solid state without any observable change over two months. To investigate the potential value of 1 as a material for p‐type organic field‐effect transistors (OFETs), top‐contact OFET devices were fabricated by vacuum deposition of 1 onto a hexamethyldisilazane (HMDS)/SiO 2 /Si substrate. The best hole mobility performance was 2.2 cm 2 V −1 s −1 . This is the first report of stable heptacene being used in an effective device and examined for its charge carrier properties.