121st General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation for 2018 DOW Chemical Korea Award
Room No. Room 202A
Time THU 11:27-:
Code KCS.O-10
Subject High-Field-Effect Mobility of Low-Crystallinity Conjugated Polymers with Localized Aggregates
Authors SUNG YUN SON, Yebyeol Kim, Junwoo Lee, Gang-Young Lee, Won-Tae Park1, Yong-Young Noh1, Chan Eon Park*, Taiho Park*
Department of Chemical Engineering, Pohang University of Science and Technology, Korea
1Department of Energy and Materials Engineering, Dongguk University, Korea
Abstract Charge carriers typically move faster in crystalline regions than in amorphous regions in conjugated polymers because polymer chains adopt a regular arrangement resulting in a high degree of π−π stacking in crystalline regions. In contrast, the random polymer chain orientation in amorphous regions hinders connectivity between conjugated backbones; thus, it hinders charge carrier delocalization. Various studies have attempted to enhance charge carrier transport by increasing crystallinity. However, these approaches are inevitably limited by the semicrystalline nature of conjugated polymers. Moreover, high-crystallinity conjugated polymers have proven inadequate for soft electronics applications because of their poor mechanical resilience. Increasing the polymer chain connectivity by forming localized aggregates via π-orbital overlap among several conjugated backbones in amorphous regions provides a more effective approach to efficient charge carrier transport. A simple strategy relying on the density of random copolymer alkyl side chains was developed to generate these localized aggregates. In this strategy, steric hindrance caused by these side chains was modulated to change their density. Interestingly, a random polymer exhibiting low alkyl side chain density and crystallinity displayed greatly enhanced field-effect mobility (1.37 cm2/(v·s)) compared with highly crystalline poly(3-hexylthiophene).
E-mail sonsy1777@postech.ac.kr