Control of Molecular Orientation of Organic Semiconductor on a Functional Organic Gate Insulator and the Effect on TFT Characteristics

Abstract

The control of molecular alignment of an organic semiconductor is expected to improve the device performance of organic TFTs. We have used a gate insulating films with a molecular alignment capability to improve the device performance, in which several kinds of photo-sensitive gate insulating films having different molecular alignment capabilities are studied. Two methods of spin-coating and vacuum-evaporation methods are used to deposit an organic semiconductor film on the gate insulating film. From X-ray measurements, we prove that increasing molecular alignment capability is most important for getting a well-oriented organic film in a spin-coating method, but it is of secondary importance for a vacuum evaporated film.