Because of its high compatibility with conventional microfabrication processing technology, epitaxial graphene (EG) grown on SiC shows exceptional promise for graphene-based electronics. However, to date, a detailed understanding of the transformation from three-layer SiC to monolayer graphene is still lacking. Here, we demonstrate the direct atomic-scale observation of EG growth on a SiC (11̅00) surface at 1,000 °C by in situ transmission electron microscopy in combination with ab initio molecular dynamics (AIMD) simulations. Our detailed analysis of the growth dynamics of monolayer graphene reveals that three SiC (11̅00) layers decompose successively to form one graphene layer. Sublimation of the first layer causes the formation of carbon clusters containing short chains and hexagonal rings, which can be considered as the nuclei for graphene growth. Decomposition of the second layer results in the appearance of new chains connecting to the as-formed clusters and the formation of a network with large pores. Finally, the carbon atoms released from the third layer lead to the disappearance of the chains and large pores in the network, resulting in a whole graphene layer. Our study presents a clear picture of the epitaxial growth of the monolayer graphene from SiC and provides valuable information forfuture developments in SiC-derived EG technology.

中文翻译：

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SiC单层石墨烯生长的原位原子尺度观察

由于其与常规微加工工艺技术的高度兼容性，在SiC上生长的外延石墨烯（EG）对于基于石墨烯的电子产品显示出无与伦比的前景。但是，迄今为止，仍缺乏对从三层SiC到单层石墨烯的转变的详细理解。在这里，我们通过原位透射电子显微镜结合从头算证明了在1000°C下SiC（11̅00）表面上EG生长的原子级直接观察。分子动力学（AIMD）模拟。我们对单层石墨烯的生长动力学的详细分析表明，三层SiC（11̅00）层连续分解形成一层石墨烯层。第一层的升华导致形成包含短链和六边形环的碳簇，可以将其视为石墨烯生长的核。第二层的分解导致出现新链，这些新链连接到已形成的簇，并形成具有大孔的网络。最后，从第三层释放的碳原子导致链中的链消失和网络中的大孔消失，从而形成整个石墨烯层。