Choi Jin Sik, Choi Hongkyw, Kim Ki-Chul, Jeong Hu Young, Yu Young-Jun, Kim Jin Tae, Kim Jin-Soo, Shin Jin-Wook, Cho Hyunsu, Choi Choon-Gi
Creative Research Center for Graphene Electronics, Electronics and Telecommunications Research Institute (ETRI), 218 Gajeong-ro, Yuseong-gu, Daejeon 305-700, Korea.
Department of Advanced Chemical Engineering, Mokwon University, Daejeon 302-729, Korea.
Sci Rep. 2016 Apr 15;6:24525. doi: 10.1038/srep24525.
Graphene has been received a considerable amount of attention as a transparent conducting electrode (TCE) which may be able to replace indium tin oxide (ITO) to overcome the significant weakness of the poor flexibility of ITO. Given that graphene is the thinnest 2-dimensional (2D) material known, it shows extremely high flexibility, and its lateral periodic honeycomb structure of sp(2)-bonded carbon atoms enables ~2.3% of incident light absorption per layer. However, there is a trade-off between the electrical resistance and the optical transmittance, and the fixed absorption rate in graphene limits is use when fabricating devices. Therefore, a more efficient method which continuously controls the optical and electrical properties of graphene is needed. Here, we introduce a method which controls the optical transmittance and the electrical resistance of graphene through various thicknesses of the top Cu layers with a Cu/Ni metal catalyst structure used to fabricate a planar mesh pattern of single and multi-layer graphene. We exhibit a continuous transmittance change from 85% (MLG) to 97.6% (SLG) at an incident light wavelength of 550 nm on graphene samples simultaneously grown in a CVD quartz tube. We also investigate the relationships between the sheet resistances.
石墨烯作为一种透明导电电极（TCE）受到了广泛关注，它有望取代氧化铟锡（ITO），以克服ITO柔韧性差这一显著弱点。鉴于石墨烯是已知最薄的二维（2D）材料，它具有极高的柔韧性，其由sp(2)键合碳原子构成的横向周期性蜂窝结构使得每层能吸收约2.3%的入射光。然而，在电阻和光学透过率之间存在权衡，并且石墨烯中固定的吸收率限制了其在制造器件时的应用。因此，需要一种能持续控制石墨烯光学和电学性质的更有效方法。在此，我们介绍一种方法，该方法通过具有Cu/Ni金属催化剂结构的不同厚度的顶部Cu层来控制石墨烯的光学透过率和电阻，该结构用于制造单层和多层石墨烯的平面网格图案。在CVD石英管中同时生长的石墨烯样品上，我们在550 nm的入射光波长下展示了从85%（多层石墨烯）到97.6%（单层石墨烯）的连续透过率变化。我们还研究了薄层电阻之间的关系。
