School of Mechanical and Advanced Materials Engineering, Ulsan National Institute of Science and Technology, Ulsan 689-798, Republic of Korea.
ACS Appl Mater Interfaces. 2012 Mar;4(3):1777-82. doi: 10.1021/am3000177. Epub 2012 Mar 19.
Few-layer graphene films with a controllable thickness were grown on a nickel surface by rapid thermal annealing (RTA) under vacuum. The instability of nickel films in air facilitates the spontaneous formation of ultrathin (<2-3 nm) carbon- and oxygen-containing compounds on a nickel surface; thus, the high-temperature annealing of the nickel samples without the introduction of intentional carbon-containing precursors results in the formation of graphene films. From annealing temperature and ambient studies during RTA, it was found that the evaporation of oxygen atoms from the surface is the dominant factor affecting the formation of graphene films. The thickness of the graphene layers is strongly dependent on the RTA temperature and time, and the resulting films have a limited thickness (<2 nm), even for an extended RTA time. The transferred films have a low sheet resistance of ~0.9 ± 0.4 kΩ/sq, with ~94% ± 2% optical transparency, making them useful for applications as flexible transparent conductors.
通过在真空中进行快速热退火（RTA），在镍表面生长出具有可控厚度的少层石墨烯薄膜。镍膜在空气中的不稳定性促进了镍表面上超薄（<2-3nm）的含碳和含氧化合物的自发形成；因此，在不引入有意含碳前体的情况下对镍样品进行高温退火会导致石墨烯薄膜的形成。通过 RTA 期间的退火温度和环境研究，发现氧原子从表面的蒸发是影响石墨烯薄膜形成的主要因素。石墨烯层的厚度强烈依赖于 RTA 温度和时间，并且所得薄膜的厚度有限（<2nm），即使 RTA 时间延长也是如此。转移的薄膜具有低的方阻约 0.9±0.4kΩ/sq，约 94%±2%的光学透明度，使它们可用于作为柔性透明导体的应用。
