[16p-M_B104-1~18] 12.4 Organic light-emitting devices, organic transistors, and flexible devices

2:00 PM - 2:15 PM JST(5:00 AM - 5:15 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation Award

[16p-M_B104-1] Molecular Dynamics Simulations for the Structural Transition of Liquid-Crystalline Organic Semiconductor Thin Films under Tensile Strain

〇Rikuo Suzuki¹, Hiroyuki Matsui¹ (1.ROEL, Yamagata Univ.)

Keywords:

Liquid-crystalline organic semiconductor,Tensile strain,Molecular dynamics simulation

We investigated tensile deformation of bilayer thin films of the OFET semiconductors Ph-BTBT-C10 and Ph-BTNT-C10 by all-atom molecular dynamics. Crystal structures from single-crystal XRD were rebuilt in GROMACS using GAFF and RESP charges (B3LYP/6-31G*). Simulations were run at 300 K in the NVT ensemble with a v-rescale thermostat while the cell was expanded along (010) at 0.2 m/s. Stress–strain curves showed that Ph-BTNT-C10 sustained elastic deformation up to about twice the strain of Ph-BTBT-C10, exceeding what a simple van der Waals/cohesive-energy difference (~1.10) would predict. Structurally, Ph-BTBT-C10 preserved the herringbone packing, whereas Ph-BTNT-C10 exhibited strain-induced transitions from herringbone to brickwork and then to π-stacked motifs. We attribute the contrasting strain tolerance to differences in molecular shape and liquid-crystalline character, which control long-axis slip at yielding. This work was supported by JST SPRING.