We fabricated nanowires of a conjugated oligomer and applied them to organic field-effect transistors (OFETs). The supramolecular assemblies of a thienoisoindigo-based small molecular organic semiconductor (TIIG-Bz) were prepared by co-precipitation with 2-bromobenzaldehyde (2-BBA) via a combination of halogen bonding (XB) between the bromide in 2-BBA and electron-donor groups in TIIG-Bz, and chalcogen bonding (CB) between the aldehyde in 2-BBA and sulfur in TIIG-Bz. It was found that 2-BBA could be incorporated into the conjugated planes of TIIG-Bz via XB and CB pairs, thereby increasing the π − π stacking area between the conjugated planes. As a result, the driving force for one-dimensional growth of the supramolecular assemblies via π − π stacking was significantly enhanced. TIIG-Bz/2-BBA nanowires were used to fabricate OFETs, showing significantly enhanced charge transfer mobility compared to OFETs based on pure TIIG-Bz thin films and nanowires, which demonstrates the benefit of nanowire fabrication using 2-BBA.
Bibliographical noteFunding Information:
J.P. acknowledges Prof. Tsunehiro Tanaka and Prof. Kentaro Teramura in Kyoto University for an access to the UV-vis-NIR spectrometer equipped with an integrating sphere. This work was supported by National Research Foundation of Korea (NRF) grants funded by the Korea government (NRF-2016R1D1A1A02937538, 2017M2A2A6A01021427, and 2018R1A2A1A05077194 ), and by JSPS KAKENHI (Grant Number 17H06791). Experiments on the PLS-II 6D and 9A beamlines were supported in part by MEST, POSTECH, and UNIST UCRF.
© 2018, The Author(s).