Intermolecular interactions of an isoindigo-based organic semiconductor with various crosslinkers through hydrogen bonding.

Three crosslinkers (1,4-diaminobutane, 1,8-diaminooctane, and 1,6-hexanediol) were selected to produce hydrogen-bonded networks using a simple and effective method. The effects of these crosslinkers on the arrangement of crystalline structures were successfully studied using X-ray diffraction and high-voltage electron microscopy. The hydrogen-bonded isoindigo-based small molecules with 1,4-diaminobutane showed the best performance, with a crystal structure showing long-range order, due to the more suitable length of the 1,4-diaminobutane chain. The hole mobility estimated from hole-only devices based on isoindigo was enhanced from 1.24 × 10 -6 cm 2 V -1 s -1 to 7.28 × 10 -4 cm 2 V -1 s -1 as a result of the inclusion of this crosslinker, due to the formation of stronger interactions between the molecules.