Molecular design and crystallization process control for thin sheet-shaped organic semiconductor crystals with two-dimensional packing

Abstract

Sheet-liked organic semiconductor crystals with two-dimensional (2D) packed structures play an essential role in practical applications of high-property optoelectronic devices. Here, we report a practical example in combination with chemical structures and crystallization engineering to construct a balanced 2D network for organic thin sheet-shaped crystals. The introduction of the cyano group enabled the formation of hydrogen bonds, promoting the in-plane 2D network construction both in strength and direction with π⋯π (or C–H⋯π) interactions. Through changing the chamber pressure and growth temperature, we realized a macroscopic morphology adjustment from rods to sheets with the same single crystal structure, ascribed to the relative strength changes of different facet energies. Such a macroscopic dimension control combined with supramolecular chemistry and crystal engineering offers a new perspective for boosting further developments for 2D stacked organic semiconductor crystals.