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Báo cáo hóa học: " Graphitic carbon growth on crystalline and amorphous oxide substrates using molecular beam epitaxy"

Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : Graphitic carbon growth on crystalline and amorphous oxide substrates using molecular beam epitaxy | Jerng et al. Nanoscale Research Letters 2011 6 565 http www.nanoscalereslett.eom content 6 1 565 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Graphitic carbon growth on crystalline and amorphous oxide substrates using molecular beam epitaxy Sahng-Kyoon Jerng1 Dong Seong Yu1 Jae Hong Lee1 Christine Kim2 Seokhyun Yoon2 and Seung-Hyun Chun1 Abstract We report graphitic carbon growth on crystalline and amorphous oxide substrates by using carbon molecular beam epitaxy. The films are characterized by Raman spectroscopy and X-ray photoelectron spectroscopy. The formations of nanocrystalline graphite are observed on silicon dioxide and glass while mainly sp2 amorphous carbons are formed on strontium titanate and yttria-stabilized zirconia. Interestingly flat carbon layers with high degree of graphitization are formed even on amorphous oxides. Our results provide a progress toward direct graphene growth on oxide materials. PACS 81.05.uf 81.15.Hi 78.30.Ly. Keywords graphite molecular beam epitaxy Raman oxide Introduction Graphene growth on Ni or Cu by chemical vapor deposition CVD is now well established. However the CVD graphene needs to be transferred onto insulating substrates for application which may degrade the quality and bring complications to the manufacturing process. This is why direct graphene growth on insulator is still intensively being studied. Notably the growth on oxide is of great interest because graphene is expected to face current metal-oxide semiconductor MOS technology through an oxide layer. Recent studies have shown some accomplishments toward this goal by using CVD 1-3 . Here we attempt molecular beam epitaxy MBE of carbon onto several oxide substrates to figure out the potential of graphene growth. So far carbon MBE has been applied mostly on group IV semiconductors 4-7 where graphitic carbon growth was observed. We have shown previously that nanocrystalline graphite NCG can be formed on sapphire Al2O3 and observed