[1Gp01-06] Thin Film (TF)

[1Gp03] Growth and orientation control of organic ionic plastic crystals by ionic liquid-assisted vacuum deposition

*Yota Matsuoka¹, Shingo Maruyama¹, Kenichi Kaminaga¹, Yuji Matsumoto¹ (1. Graduate School of Engineering, Tohoku University)

We report the growth and orientation control of thin films of organic ionic plastic crystal 1-ethyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide ([C₂mpyr][TFSA]) by an ionic liquid (IL)-assisted vacuum deposition method. The thin films grown without IL showed either polycrystalline or (010) oriented structures depending on the deposition temperature, while (100)-oriented [C₂mpyr][TFSA] crystallites were preferentially grown in the IL-assisted process. In addition, polycrystalline films were grown when using a non-polar liquid instead of the IL, suggesting that the polar nature of IL stabilized the (100) plane of [C₂mpyr][TFSA] crystallites during the crystal growth process. The degree of crystal orientation of thin films grown by the IL-assisted process depended on the growth temperature, probably due to their different crystal growth mechanisms for the different temperatures, which was suggested by in situ optical microscope observation during/after the deposition.