[18p-D63-1~17] 12.1 Fabrications and Structure Controls

2:15 PM - 2:30 PM JST(5:15 AM - 5:30 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation Award

[18p-D63-5] Optimal Annealing Conditions for Organic Thin Film Transistors Using Ph-BTBT-10 Revealed by Infrared Spectroscopy and X-ray Diffraction

〇(D)Takayuki Oka¹, Nobutaka Shioya¹, Hiroki Nakano², Hiroaki Iino², Takeshi Hasegawa¹ (1.ICR, Kyoto Univ., 2.FIRST, Tokyo Tech.)

Keywords:

organic semiconductor,liquid crystal phase,polymorphism

2-Decyl-7-phenyl[1]benzothieno[3,2-b][1]benzothiophene(Ph-BTBT-10) has excellent performances as p-type semiconductors for organic thin-film transistors, which are enhanced by thermal annealing via transformations of the molecular packing structure. In this work, thin films of Ph-BTBT-10 are prepared by spin coating, and the effect of post annealing on the molecular aggregation structure is investigated by infrared (IR) spectroscopy in combination with X-ray diffraction. We focus on the CH₂ antisymmetric stretching vibration band of the decyl chain in IR spectra, which is sensitive to the chain conformation. The results show that the disordered alkyl side chains prevent the formation of ordered crystalline structures in the crystallization process of thermal annealing. In the presentation, the effects of annealing temperature, and cooling rate on the film structure will be discussed in detail to determine the optimal annealing conditions for the crystallization.