Writing graphene: Ion-beam modification of thin polymer layers

我们提出了一种全新的石墨烯生长方法。与剥离或表面层反应相反，我们将实现石墨烯的水平生长。聚合物或其他含碳前体将在特殊开发的扫描模式下通过离子照射转化为石墨烯层。与区域熔化过程类似，离子束将沿着前驱体膜逐渐移动，从而在束边界处引发石墨烯生长。通过改进我们的扫描辐照技术，我们计划实现1纳米数量级的光束边缘锐度。该值与石墨化层中碰撞级联的横向尺寸以及石墨烯薄片的尺寸相当。我们期望这种方法可以在任意衬底上提供大面积的石墨烯薄膜。为了研究石墨烯的生长过程，将在环境条件和特高压条件下进行拉曼光谱，AFM， STM， SEM和TEM。此外，将通过测量其输运性质来表征薄膜，包括电场和磁场的影响，如霍尔效应等。为了获得光滑的纳米厚前驱体层，将应用几种材料和沉积工艺。通过使用有助于石墨烯生长的衬底（Cu, Ni， Co等），我们希望通过扫描离子辐照显著降低工艺温度，并期望生长的薄膜具有有趣的传输特性。

We propose a radically new method of graphene growth. In contrast to exfoliation or surface layer reactions we will realize a horizontal graphene growth. Polymers or other carbon containing precursors will be converted into a graphene layer by ion irradiation in a specially developed scanning mode. In analogy with a zone melting process, the ion beam will move gradually along the precursor film initiating graphene growth at the beam border. By improving our scanning irradiation technique we plan to achieve a sharpness of the beam edge of the order of 1 nm. This value is comparable with the lateral size of a collision cascade in the graphitized layer as well as the size of graphene flakes. We expect that this procedure can provide large-area graphene films on arbitrary substrates. Raman spectroscopy, AFM, STM in ambient conditions and in UHV, SEM and TEM will be performed in order to investigate the process of graphene growth. Furthermore, the films will be characterized by measurements of their transport properties including influence of electric and magnetic fields, like Hall effect, etc. Several materials and deposition processes will be applied in order to obtain smooth, nanometer thick precursor layers. By using substrates, which assist graphene growth (Cu, Ni, Co etc.) we hope to achieve a significant reduction of the process temperatures by scanning ion irradiation, and expect interesting transport properties of the grown films.