유연반도체의 분자 배향과 후처리 공정을 통한 고성능 유연인쇄전자 회로 개발 연구

Abstract

Printed and flexible electronics based on soluble conjugated organic molecules have drawn tremendous interest as a new paradigm for the fabrication of large-area and low-cost optoelectronics and electronics applications. Those polymers should be preferably aligned in the perpendicular direction through the active channel of organic field-effect transistors (OFETs). Morphological control and structural ordering of the conjugated polymers via large area printing method is an important issue in order to achieve high performance OFETs and its electronic circuitry. In this study, we report various directional printing methods (off-centered spin-coating, dip-coating, and bar-coating) for preferable arrangement of conjugated polymers, such as high mobility PCDTFBT and DPPT-TT. Those polymer OFETs showed high charge carrier mobilities as high as 11 cm2V -1s -1 and balanced ambipolar charge transport behavior in the top-gated OFET structure with polymer dielectrics. This remarkable enhancement is mostly attributed to improved arrangement and ordering of polymer chains through the active channel and better uniformity of OFET parameters is also obtained by this large-area printing techniques. Moreover, high-k fluorinated polymer dielectrics significantly contribute to increase high charge carrier density under low voltage conditions. Finally, higher mobilities and well-balanced P-channel and N-channel characteristics in comparison to conventional coating methods was successfully applied to develop complementary-like printed circuits, it is expected to be realize high performance flexible and wearable electronic devices via costeffective simple printing methods.