Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea. KAIST Institute for the Nanocentury, Daejeon 34141, Korea.
Nanotechnology. 2016 Sep 9;27(36):365705. doi: 10.1088/0957-4484/27/36/365705. Epub 2016 Aug 2.
The direct transfer of graphene using polydimethylsiloxane (PDMS) stamping has advantages such as a 'pick-and-place' capability and no chemical residue problems. However, it is not easy to apply direct PDMS stamping to graphene grown via chemical vapor deposition on rough, grainy metal surfaces due to poor contact between the PDMS and graphene. In this study, graphene consisting of a mixture of monolayers and multiple layers grown on a rough Ni surface was directly transferred without the use of an adhesive layer. Liquid PDMS was cured on graphene to effect a conformal contact with the graphene. A fast release of graphene from substrate was achieved by carrying out wet-etching-assisted mechanical peeling. We also carried out a thermal post-curing of PDMS to control the level of adhesion between PDMS and graphene and hence facilitate a damage-free release of the graphene. Characterization of the transferred graphene by micro-Raman spectroscopy, SEM/EDS and optical microscopy showed neither cracks nor contamination from the transfer. This technique allows a fast and simple transfer of graphene, even for multilayer graphene grown on a rough surface.
使用聚二甲基硅氧烷（PDMS）压印直接转移石墨烯具有“拾取和放置”能力和无化学残留问题等优点。然而，由于 PDMS 与石墨烯之间接触不良，直接将 PDMS 压印应用于在粗糙、粒状金属表面上通过化学气相沉积生长的石墨烯并不容易。在这项研究中，在粗糙的 Ni 表面上生长的由单层和多层混合组成的石墨烯在不使用粘合剂层的情况下被直接转移。液态 PDMS 在石墨烯上固化，以实现与石墨烯的共形接触。通过进行湿蚀刻辅助机械剥离，可以快速将石墨烯从衬底上释放。我们还对 PDMS 进行了热后固化处理，以控制 PDMS 和石墨烯之间的粘附水平，从而便于无损伤地释放石墨烯。通过微拉曼光谱、SEM/EDS 和光学显微镜对转移的石墨烯进行的表征表明，转移过程中没有出现裂纹或污染。这种技术允许快速简单地转移石墨烯，即使是在粗糙表面上生长的多层石墨烯也可以。
