Enhancement of the p-channel performance of sulfur-bridged annulene through a donor–acceptor co-crystal approach†
By introducing naphthalene diimide into the meso-diphenyl tetrathiaannulene[2,1,2,1], a natural donor–acceptor co-crystal was prepared. In this co-crystal, donor and acceptor alternatingly stack into one-dimensional columns along the π–π stacking direction. With π–π interaction among the donor molecules, no effective π–π overlapping between DPNDIs in the acceptor columns was observed. Microcrystal transistor devices based on this D–A co-crystal displayed higher hole transport performance compared to the pristine crystals of donor molecules. Quantum calculation confirmed the absence of electron transport pathways and the super exchange between the adjacent donor and acceptor. From the diversity and versatility of the donor and acceptor used, we believe that the strategy developed here would be readily employed to tune the charge transport of organic semiconductors.