Growth of Semiconducting Graphene on Palladium
Growth of Semiconducting Graphene on Palladium
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DOI：
10.1021/nl902140j
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发表时间：
2009-12-01
期刊：
影响因子：
10.8
通讯作者：
Kodambaka, Suneel
中科院分区：
文献类型：
--
作者：
Kwon, Soon-Yong;Ciobanu, Cristian V.;Kodambaka, Suneel
我们报道了在723至1023 K温度下乙烯沉积过程中石墨烯在Pd（111）上生长的原位扫描隧道显微镜研究。我们观察到单层石墨烯岛的形成，大小为200-2000埃，以Pd表面台阶为界。令人惊讶的是，石墨烯岛的地形图像对比度与隧道偏置相反，表明具有半导体行为。扫描隧道光谱测量证实石墨烯岛是半导体的，带隙为0.3 +/- 0.1 eV。基于密度泛函理论计算，我们认为带隙的打开是由于石墨烯和Pd衬底之间的强相互作用。我们的研究结果表明，通过直接沉积在强相互作用的衬底上，可以为未来的碳基纳米电子器件制备半导体石墨烯层。
We report in situ scanning tunneling microscopy studies of graphene growth on Pd(111) during ethylene deposition at temperatures between 723 and 1023 K. We observe the formation of monolayer graphene islands, 200-2000 angstrom in size, bounded by Pd surface steps. Surprisingly, the topographic image contrast from graphene islands reverses with tunneling bias, suggesting a semiconducting behavior. Scanning tunneling spectroscopy measurements confirm that the graphene islands are semiconducting, with a band gap of 0.3 +/- 0.1 eV. On the basis of density functional theory calculations, we suggest that the opening of a band gap is due to the strong interaction between graphene and the Pd substrate. Our findings point to the possibility of preparing semiconducting graphene layers for future carbon-based nanoelectronic devices via direct deposition onto strongly interacting substrates.