Department of Chemical and Biomolecular Engineering (BK21 program) and Institute for the BioCentury, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Korea.
Langmuir. 2010 Aug 3;26(15):12902-8. doi: 10.1021/la101698j.
Poly(3,4-ethylenedioxythiophene) (PEDOT)-based film has relatively high conductivity, flexibility, and transmittance. However, the improvement for mechanical strength and conductivity is still required to be adopted for commercial applications. Graphene, a one atom thick planar sheet of sp(2)-bonded carbon atoms, is considered as an ideal nanocomposite material for these purposes. In this study, we have developed PEDOT and graphene composite films, two-layered graphene/PEDOT and three-layered graphene/PEDOT/graphene, by using a spin-coating method. The conductivity of a 32 nm thick PEDOT film was improved more than twice by graphene deposition, while the high transmittance of the composite film was maintained over 90%. The mechanical strength of the PEDOT and graphene composite film shows 6-fold enhancement over the pristine PEDOT film. Because of the contribution of graphene layer for enhancing the mechanical strength, a 44 nm thick graphene/PEDOT/graphene could be obtained as a free-standing film by delaminating the graphene layer from the glass substrate under a weak base solution. These results imply that the graphene not only improves the conductivity and mechanical strength of PEDOT but also enables to produce a free-standing film which could find a variety of applications in the fields of organic electronic, sensors, and optoelectronics.
基于聚（3,4-亚乙基二氧噻吩）（PEDOT）的薄膜具有相对较高的电导率、柔韧性和透光率。然而，为了商业应用，仍需要提高其机械强度和电导率。石墨烯是一种由 sp(2)键合碳原子组成的单层平面薄片，被认为是一种理想的纳米复合材料。在本研究中，我们通过旋涂法开发了PEDOT 和石墨烯复合薄膜，包括两层石墨烯/PEDOT 和三层石墨烯/PEDOT/石墨烯。通过石墨烯沉积，32nm 厚的 PEDOT 薄膜的电导率提高了两倍以上，而复合薄膜的高透光率保持在 90%以上。PEDOT 和石墨烯复合薄膜的机械强度比原始 PEDOT 薄膜提高了 6 倍。由于石墨烯层有助于提高机械强度，因此可以在弱碱溶液中将石墨烯层从玻璃基底上剥离，获得厚度为 44nm 的独立石墨烯/PEDOT/石墨烯薄膜。这些结果表明，石墨烯不仅可以提高 PEDOT 的电导率和机械强度，而且还可以制备独立的薄膜，这在有机电子、传感器和光电子等领域有广泛的应用。
