Department of Materials Science & Engineering, Seoul National University, Seoul 151-744, Republic of Korea.
Phys Chem Chem Phys. 2014 Feb 21;16(7):3087-94. doi: 10.1039/c3cp54748e.
One of the major challenges for the practical application of graphene is the large scale synthesis of uniform films with high quality at lower temperature. Here, we demonstrate the use of Ag-plated Cu substrates in the synthesis of high-quality graphene films via chemical vapor deposition (CVD) of methane gas at temperatures as low as 900 °C. Various experimental analyses show that the plated Ag diffuses into Cu to form a uniform Cu-Ag alloy that suppresses the formation of multilayer nucleation and decreases the activation energy of precursor formation, leading to a lower synthesis temperature with enhanced monolayer coverage. In addition, we also observed an unusual Ag-assisted abnormal grain growth of Cu into the cube texture with larger grain sizes and reduced grain boundaries, which is believed to provide the homogeneous environment needed for uniform graphene growth.
在石墨烯的实际应用中，主要挑战之一是在较低温度下大规模合成具有高质量的均匀薄膜。在这里，我们通过在 900°C 以下的温度下用甲烷气体进行化学气相沉积（CVD），展示了在镀银的 Cu 衬底上合成高质量石墨烯薄膜的方法。各种实验分析表明，镀银 Ag 扩散到 Cu 中形成均匀的 Cu-Ag 合金，抑制了多层形核的形成，并降低了前体形成的激活能，从而降低了合成温度，同时提高了单层覆盖率。此外，我们还观察到了一种异常的 Ag 辅助的 Cu 异常晶粒长大，形成了具有更大晶粒尺寸和更少晶界的立方织构，这被认为提供了均匀石墨烯生长所需的均匀环境。
