Surface-Assisted Reactions toward Formation of Graphene Nanoribbons on Au(110) Surface

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• 作者：Lorenzo Massimi ; Oualid Ourdjini ; Leif Lafferentz ; Matthias Koch ; Leonhard Grill ; Emanuele Cavaliere ; Luca Gavioli ; Claudia Cardoso ; Deborah Prezzi ; Elisa Molinari ; Andrea Ferretti ; Carlo Mariani ; Maria Grazia Betti
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：February 5, 2015
• 年：2015
• 卷：119
• 期：5
• 页码：2427-2437
• 全文大小：627K
• ISSN：1932-7455

文摘

Scanning tunneling microscopy and X-ray spectroscopy measurements are combined to first-principles simulations to investigate the formation of graphene nanoribbons (GNRs) on Au(110), as based on the surface-mediated reaction of 10,10鈥?dibromo-9,9鈥?bianthracene (DBBA) molecules. At variance with Au(111), two different pathways are identified for the GNR self-assembly on Au(110), as controlled by both the adsorption temperature and the surface coverage of the DBBA molecular precursors. Room-temperature DBBA deposition on Au(110) leads to the same reaction steps obtained on Au(111), even though with lower activation temperatures. For DBBA deposition at 470 K, the cyclodehydrogenation of the precursors preceds their polymerization, and the GNR formation is fostered by increasing the surface coverage. While the initial stages of the reaction are found to crucially determine the final configuration and orientation of the GNRs, the molecular diffusion is found to limit in both cases the formation of high-density long-range ordered GNRs. Overall, the direct comparison between the Au(110) and Au(111) surfaces unveils the delicate interplay among the different factors driving the growth of GNRs.