Department of Aerospace Engineering and Engineering Mechanics, Research Center for the Mechanics of Solids, Structures and Materials, ‡Department of Mechanical Engineering and The Materials Science and Engineering Program, and §Department of Electrical and Computer Engineering, The University of Texas at Austin Austin, Texas 78712, United States.
ACS Nano. 2015 Feb 24;9(2):1325-35. doi: 10.1021/nn505178g. Epub 2015 Feb 6.
A very fast, dry transfer process based on mechanical delamination successfully effected the transfer of large-area, CVD grown graphene on copper foil to silicon. This has been achieved by bonding silicon backing layers to both sides of the graphene-coated copper foil with epoxy and applying a suitably high separation rate to the backing layers. At the highest separation rate considered (254.0 μm/s), monolayer graphene was completely transferred from the copper foil to the target silicon substrate. On the other hand, the lowest rate (25.4 μm/s) caused the epoxy to be completely separated from the graphene. Fracture mechanics analyses were used to determine the adhesion energy between graphene and its seed copper foil (6.0 J/m(2)) and between graphene and the epoxy (3.4 J/m(2)) at the respective loading rates. Control experiments for the epoxy/silicon interface established a rate dependent adhesion, which supports the hypothesis that the adhesion of the graphene/epoxy interface was higher than that of the graphene/copper interface at the higher separation rate, thereby providing a controllable mechanism for selective transfer of graphene in future nanofabrication systems such as roll-to-roll transfer.
一种基于机械分层的快速、干燥的转移工艺成功地将大面积、CVD 生长的石墨烯从铜箔转移到硅衬底上。这是通过将硅背衬层用环氧树脂键合到涂有石墨烯的铜箔的两侧，并对背衬层施加适当高的分离速率来实现的。在所考虑的最高分离速率（254.0 μm/s）下，单层石墨烯完全从铜箔转移到目标硅衬底上。另一方面，最低速率（25.4 μm/s）导致环氧树脂完全与石墨烯分离。断裂力学分析用于确定在各自加载速率下石墨烯与其种子铜箔（6.0 J/m(2)）和石墨烯与环氧树脂（3.4 J/m(2)）之间的粘附能。对环氧树脂/硅界面的控制实验建立了一个依赖于速率的粘附，这支持了这样一种假设，即在较高的分离速率下，石墨烯/环氧树脂界面的粘附力高于石墨烯/铜界面的粘附力，从而为未来的纳米制造系统（如卷对卷转移）提供了一种可控的石墨烯选择性转移机制。
