Optical Anisotropy of Pentacene Molecules on a Photoaligning Gate Insulator Layer for Organic Thin-Film Transistors

摘要

We report on the surface-induced molecular order and the optical anisotropy of the pentacene thin film on a photoaligning buffer layers. The photopolymer, showing an anchoring transition from the vertical alignment to the planar alignment by the exposure of a linearly polarized ultraviolet light, was used as a buffer layer to control the structural order of the pentacene molecules. The atomic force microscopic images revealed the recovery of void sites and the enlargement of the grain size in the pentacene film grown on the photoaligning buffer layer. It was found that the grain size and the optical anisotropy of the pentacene film were strongly correlated with each other.