Loose graphene sheets, one to a few atomic layers thick, are often observed on freshly cleaved HOPG surfaces. A straightforward technique using electrostatic attraction is demonstrated to transfer these graphene sheets to a selected substrate. Sheets from one to 22 layers thick have been transferred by this method. One sheet after initial deposition is measured by atomic force microscopy to be only an atomic layer thick (approx0.35 nm). A few weeks later, this height is seen to increase to approx0.8 nm. Raman spectroscopy of a single layer sheet shows the emergence of an intense D band which dramatically decreases as the number of layers in the sheet increase. The intense D band in monolayer graphene is attributed to the graphene conforming to the roughness of the substrate. The disruption of the C-C bonds within the single graphene layer could also contribute to this intense D band as evidenced by the emergence of a new band at 1620 cm_(-1).
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机译：在刚裂解的HOPG表面经常观察到松散的石墨烯片，厚度为一到几原子层。已证明使用静电引力的简单技术可以将这些石墨烯片转移到选定的基材上。已经通过这种方法转移了1到22层厚的薄片。初始沉积后，通过原子力显微镜测量一片，其厚度仅为原子层厚度（约0.35 nm）。几周后，该高度增加到约0.8 nm。单层薄板的拉曼光谱显示强D带的出现，该D带随着薄层中层数的增加而急剧下降。单层石墨烯中的强D带归因于石墨烯符合基底的粗糙度。单层石墨烯层内C-C键的破坏也可能会导致该强烈的D谱带，如在1620 cm _（-1）处出现新谱带所证明的。
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