Semiconductive π-conjugated system incorporated into optoelectronic devices is one of the most important factors determining the performance of the device. The mobility of the organic semiconductor should be as high as possible so that an efficient charge transport from one molecule to another is attainable. Small molecule semiconductors have been widely studied because they easily form crystalline films for the fabrication of desired high performance devices. Typical [n]acenes and [n]phenacenes exhibit ideal transistor behaviors when employed in OFETs. Among them pentacene is widely used in organic thin-film transistors and OFETs, being one of the most thoroughly investigated conjugated organic molecules with a high application potential due to a hole mobility in OFETs of up to 5.5 cm2/V·s, which exceeds that of amorphous silicon. However, two disadvantages emerged; its high sensitivity to light because of the narrow energy gaps leads to easy molecular excitation by light and high oxidation sensitivity. This leads to formation of dimers and trimers (e.g. anthracene) under ambient conditions or oxidation. On the other hand phenacenes, an isomeric form of acenes and helicenes, have been known as stable compounds in which the benzene rings are fused in a zigzag structure. Recently, it was found that [5]- and [7]phenacene, could serve as an active layer of a high performance p-channel organic thin film FET. Furthermore, [5]phenacene called picene doped with potassium and rubidium exhibits superconductivity with a maximum critical temperature Tc ∼ 18 K. Thus, [n]phenacenes may play an important role in future fabrication of stable and high-performance OFET and OLED. The difficulty in obtaining large quantities of phenacenes has hampered their broader use in optoelectronic applications. In this field we are focused on the following topics:

  • Preparation of various carbo and hetero[n]phenacenes
  • Exploration of the reactivity of hetero[n]phenacenes
  • Electrochemical study
  • Preparation of OFETs
  • Semiconducting polymers based on [n]phenacene scaffold
  • 2D and 3D coordination frameworks
  • Hetero[n]phenacenes in OPV and DSSC