School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China.
Nanotechnology. 2013 Jul 12;24(27):275302. doi: 10.1088/0957-4484/24/27/275302. Epub 2013 Jun 14.
Bilayer graphene has attracted a great deal of attention for many electronic and optical applications. Although large-area bilayer graphene can be synthesized by chemical vapor deposition (CVD), multilayer growth often occurs and subsequent processes are required to obtain uniform bilayer films. We report an efficient way of thinning multilayer graphene film by low-power CO2 laser irradiation in vacuum. With a laser power density of ~10(2) W cm(-2), pristine graphene film of 4-5 layers can be thinned to a bilayer free of defects in 30 s. Contrary to previous laser-assisted graphene thinning processes, which reduced graphene layers precisely and locally with a high power density and a small beam diameter, our approach enables high-efficiency thinning of large-area graphene film whilst using a significantly reduced power density and an increased laser beam diameter.
双层石墨烯因其在许多电子和光学应用中的潜力而受到广泛关注。虽然化学气相沉积（CVD）可以合成大面积的双层石墨烯，但通常会发生多层生长，需要后续工艺来获得均匀的双层薄膜。我们报告了一种通过低功率 CO2 激光在真空中减薄多层石墨烯薄膜的有效方法。在激光功率密度约为 10(2) W cm(-2)的条件下，未经处理的 4-5 层石墨烯薄膜可在 30 秒内减薄至无缺陷的双层结构。与之前的激光辅助石墨烯减薄工艺不同，后者使用高功率密度和小光束直径精确地局部减薄石墨烯层，我们的方法在使用显著降低的功率密度和增大的激光光束直径的情况下，实现了大面积石墨烯薄膜的高效减薄。
