10.1021/acs.cgd.9b00297.s001 Satoshi Watanabe Satoshi Watanabe Ryota Urata Ryota Urata Tetsuya Sato Tetsuya Sato Shintaro Ida Shintaro Ida Masashi Kunitake Masashi Kunitake Single Crystallization of an Organic Semiconductor in Hydrogel Capillaries for Transferring onto Substrates American Chemical Society 2019 C 8-BTBT solution crystal growth gel capillary crystallization method agarose gel capillary C 8-BTBT thienoacene-based glass capillary interface 2019-05-10 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Single_Crystallization_of_an_Organic_Semiconductor_in_Hydrogel_Capillaries_for_Transferring_onto_Substrates/8181671 We propose a single crystallization and transfer technique of organic semiconductors using a hydrogel capillary (gel capillary crystallization method). Single crystals of the C8-BTBT thienoacene-based organic semiconductor were prepared by crystal growth in a glass capillary filled with C8-BTBT solution in the supersaturated condition. By adjusting the concentration and temperature, selective nucleation was induced only at the air/liquid interface in the capillary. From the multiple nuclei generated at the interface, polycrystalline C8-BTBT formed near the interface. Subsequent continuous crystal growth in the capillary allowed the polycrystals to transform to a single crystal, because crystal growth was regulated along one direction in the capillary. Single-crystal growth was also induced at the air–liquid interface in an agarose gel capillary, which was made by piercing with a plastic sheet, similar to that in the glass capillary. After formation of a single crystal in the gel capillary, the single crystal was removed from the capillary and transferred onto a solid substrate by dissolution of the capillary with NaI solution.