Flip-flop dynamics in smectic liquid-crystal organic semiconductors revealed by molecular dynamics simulations

Asymmetric liquid-crystal (LC) organic semiconductors, such as 2-decyl-7-(p-tolyl)-[1]benzothieno[3,2-b][1]benzothiophene (pTol-BTBT-C10), exhibit high mobilities exceeding 10 cm2 V-1 s-1. The LC phases play important roles in thermal stability and self-assembly ordering during film deposition and annealing. In this study, we show molecular dynamics simulations of pTol-BTBT-C10 and reveal a unique mechanism of the molecular flip-flop motion at the smectic E/smectic B phase transition. Unique flip-flop motion of liquid-crystal organic semiconductor molecules responsible for phase transition was revealed by molecular dynamics simulations.