Electronic and Morphological Studies of Conjugated Polymers Incorporating a Disk-Shaped Polycyclic Aromatic Hydrocarbon Unit

• Published in: ACS applied materials & interfaces Vol. 7; no. 36; pp. 20034 - 20045
• Main Authors: He, Bo, Zhang, Benjamin A, Liu, Feng, Navarro, Amparo, Fernández-Liencres, M. Paz, Lu, Ryan, Lo, Kelvin, Chen, Teresa L, Russell, Thomas P, Liu, Yi
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 16.09.2015; American Chemical Society (ACS)
• Subjects: charge transport; MATERIALS SCIENCE; morphology; organic semiconductors; polycyclic aromatic hydrocarbon; thienoazacoronene; time-dependent density functional theory; organic semiconductors; time-dependent density functional theory; morphology; thienoazacoronene; charge transport; polycyclic aromatic hydrocarbon
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.5b04907

As more research findings have shown the correlation between ordering in organic semiconductor thin films and device performance, it is becoming more essential to exercise control of the ordering through structural tuning. Many recent studies have focused on the influence of side chain engineering on polymer packing orientation in thin films. However, the impact of the size and conformation of aromatic surfaces on thin film ordering has not been investigated in great detail. Here we introduce a disk-shaped polycyclic aromatic hydrocarbon building block with a large π surface, namely, thienoazacoronenes (TACs), as a donor monomer for conjugated polymers. A series of medium bandgap conjugated polymers have been synthesized by copolymerizing TAC with electron donating monomers of varying size. The incorporation of the TAC unit in such semiconducting polymers allows a systematic investigation, both experimentally and theoretically, of the relationships between polymer conformation, electronic structure, thin film morphology, and charge transport properties. Field effect transistors based on these polymers have shown good hole mobilities and photoresponses, proving that TAC is a promising building block for high performance optoelectronic materials.