The thiophene/phenylene co-oligomers: exotic molecular semiconductors integrating high-performance electronic and optical functionalities

The thiophene/phenylene co-oligomers are ranked as a newly occurring class of organic semiconductors. The materials are characterised by that thiophenes and phenylenes are hybridised at the molecular level with their various mutual arrangements. These molecular arrangements produce peculiar morphological features in the solid state and excellent electronic and optical properties. In this review article we outline those characteristics in light of the structure/property relationship with central emphasis upon the crystal structure and its relevance to the leading-edge optoelectronic functionalities. These topics are most suitably approached by device studies including field-effect transistors and light-emitting devices. We describe the device characteristics in close connection with current-injected lasers.