[20p-W631-1~8] New trends in computational materials science -Molecular electronics and bioelectronics

[20p-W631-5] Computer simulation of deformation effect on organic semiconductor

〇Toshihiro Shimada¹, Kie Yamakawa¹, Takashi Yanase¹, Taro Nagahama¹ (1.Hokkaido Univ.)

Keywords:organic semiconductor,deformation effect,computer simulation

When organic semiconductor is used in flexible devices, the molecular solid experiences mechanical stresses, primarily compression and expansion. We used molecular dynamics (MD) simulation to study what will happen to the organic semiconductor crystals. We used band calculation also for the structure obtained by MD. In the case of pentacene at 300K, molecules rearranges the stacking to increse the stack number when compressed. When pentacene layers are expanded, the slab splits at 25% expansion. In the case of C8-BTBT, the stack number does not change when compressed but the lattice constant and the crystal structure changes. When expanded, the slab remains connected even with more than 50% expansion. From the band calculation, the 50%-expanded C8-BTBT works as semiconductor. It is an example of "molecular fastner effect" by alkyl chains.