Donor–acceptor single cocrystal of coronene and perylene diimide: molecular self-assembly and charge-transfer photoluminescence

Abstract

The research on donor–acceptor (D–A) cocrystalline structures based on organic semiconductive molecules has drawn great attention due to their unique optical and electronic properties. Among the building block molecules, derivatives of perylene-3,4,9,10-tetracarboxylic-3,4,9,10-diimides (PTCDI) are of particular interest as these molecules form high performance n-type semiconductors with strong air stability. However, the cocrystal of PTCDIs remains challenging to fabricate, and only few D–A cocrystals of PTCDIs have been reported. Herein, we report a successful molecular self-assembly design for the PTCDI cocrystal with a donor molecule, coronene. Within the triclinic cell of the cocrystal, the PTCDI and coronene molecules achieved 1 : 1 alternated π–π stacking. The cocrystal showed clear red-shifted absorption and photoluminescence bands, implying the strong charge transfer interaction between coronene and PTCDI. Additionally, the cofacial π–π stacking between coronene and PTCDI planes favors strong one-dimensional self-assembly, leading to the formation of microsized fibril cocrystals and arrays. This presented cocrystal design strategy helps to explore new D–A cocrystalline structures, particularly with one-dimensional morphology control.