Self-assembled 1D Semiconductors: Liquid Crystalline Columnar Phase

Abstract

Organic semiconducting materials have emerged as potential alternative to inorganic silicon based semiconductors for the production of low-cost, flexible and light weight plastic electronic devices. When compared with crystalline and polymeric structures, liquid crystalline (LC) ordering in organic semiconductors favors their self-assembly into large area monodomain thin-film structures with carrier mobilities in the range from 10

H-Bonded Donor–Acceptor Units Segregated in Coaxial Columnar Assemblies: Toward High Mobility Ambipolar Organic Semiconductors

“…This organization facilitates long-range π-orbital overlap that allows, after appropriate charge injection, intracolumnar charge carrier mobilities with values close to or comparable to those of amorphous silicon. These features make columnar liquid crystals very attractive materials for use as organic semiconductors. − …”

“…It has been postulated that charge carrier transport in DLCs is intrinsically ambipolar; that is, both hole and electron transport are possible, but ambipolar behavior has only been found for a few DLCs. ,− The majority of DLCs contain electron-donor aromatic cores such as triphenylenes, phthalocyanines, and hexabenzocoronenes, and hole transport has been measured . Triphenylene-based mesogens are among the most widely studied columnar liquid crystals, and they show high hole mobility values in the columnar mesophase. − On the other hand, some electron-acceptor DLCs derived from azaheterocycles such as perylenebisimide, hexaazatriphenylene, and hexaazatrinaphthylene, to name a few, have been reported to show electron mobility. − …”