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

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 pi MIDLINE HORIZONTAL ELLIPSIS pi (or C-HMIDLINE HORIZONTAL ELLIPSIS pi) 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.

Automated summary

This study presents a practical example of constructing a balanced 2D network for organic thin sheet-shaped crystals using chemical structures and crystallization engineering, enabling the formation of hydrogen bonds and promoting in-plane 2D network construction through pi-pi (or C-H-pi) interactions. By adjusting chamber pressure and growth temperature, they successfully achieved macroscopic morphology transformation from rods to sheets with the same single crystal structure, providing a new perspective for further developments in 2D stacked organic semiconductor crystals with the combination of macroscopic dimension control, supramolecular chemistry, and crystal engineering.