[15p-PA03-1~18] 12.1 Fabrications and Structure Controls

[15p-PA03-4] Conformational Change of Alkyl Chains at Phase Transitions in Thin Films of an Asymmetric BTBT Derivative

〇Nobutaka Shioya¹, Takafumi Shimoaka¹, Shingo Maruyama², Takeshi Hasegawa¹ (1.Kyoto Univ., 2.Tohoku Univ.)

Keywords:organic semiconductor, liquid crystal, IR spectroscopy

Ph-BTBT-C₁₀ is one of the promising semiconducting materials with excellent charge transport properties for organic field-effect transistors. The structural properties of Ph-BTBT-C₁₀ thin films exhibit quite unique features due to an anisotropic shape of the molecule. This compound has a highly ordered liquid crystalline state, i.e., the smectic E (SmE) phase. The transition from the crystalline state to the SmE phase is believed to accompany melting of the alkyl chains, but no spectroscopic evidence has been found so far. In this study, we analyze the conformational change of the decyl chains in Ph-BTBT-C₁₀ thin films during the phase transition by in situ temperature-dependent measurements using infrared spectroscopy.