Hefei IRICO Epilight Technology Co.

Hefei, China

Hefei IRICO Epilight Technology Co.

Hefei, China
SEARCH FILTERS
Time filter
Source Type

Liu Z.,Huaibei Normal University | Liu Z.,Hefei University of Technology | Tang J.,Hefei University of Technology | Tang J.,Hefei IRICO Epilight Technology Co. | And 4 more authors.
Solid State Communications | Year: 2012

Few-layer graphene (FLG) was grown on Al 2O 3 (0 0 0 1) substrates at different temperatures via direct carbon atoms deposition by using solid source molecular beam epitaxy (SSMBE) method. The structural properties were characterized by reflection high energy electron diffraction (RHEED), Raman spectroscopy and near-edge X-ray absorption fine-structure (NEXAFS). The results showed that the FLG started to form at the substrate temperature of 700 °C. When the substrate temperature increased to 1300°C, the quality of the FLG was the best and the layer number was estimated to be less than 5. At higher substrate temperature (1400°C or above), the crystalline quality of the FLG would be deteriorated. Our experiment results demonstrated that the substrate temperature played an important role on the FLG layer formation on Al 2O 3 (0 0 0 1) substrates and the related growth mechanism was briefly discussed. © 2012 Elsevier Ltd. All rights reserved.


Tang J.,Hefei University of Technology | Tang J.,Hefei IRICO Epilight Technology Co. | Kang C.-Y.,Hefei University of Technology | Li L.-M.,Hefei University of Technology | And 4 more authors.
Chinese Physics B | Year: 2012

A method for growing graphene on a sapphire substrate by depositing an SiC buffer layer and then annealing at high temperature in solid source molecular beam epitaxy (SSMBE) equipment was presented. The structural and electronic properties of the samples were characterized by reflection high energy diffraction (RHEED), X-ray diffraction Φ scans, Raman spectroscopy, and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. The results of the RHEED and Φ scan, as well as the Raman spectra, showed that an epitaxial hexagonal α-SiC layer was grown on the sapphire substrate. The results of the Raman and NEXAFS spectra revealed that the graphene films with the AB Bernal stacking structure were formed on the sapphire substrate after annealing. The layer number of the graphene was between four and five, and the thickness of the unreacted SiC layer was about 1-1.5 nm. © 2012 Chinese Physical Society and IOP Publishing Ltd.


Tang J.,Hefei University of Technology | Tang J.,Hefei IRICO Epilight Technology Co. | Kang C.-Y.,Hefei University of Technology | Li L.-M.,Hefei University of Technology | Xu P.-S.,Hefei University of Technology
Wuli Huaxue Xuebao/ Acta Physico - Chimica Sinica | Year: 2011

Graphene is a newly discovered material with many functions. The preparation of graphene on suitable substrates is a challenge in the material preparation field. In this paper, graphene thin films were grown on Si substrates covered with SiC buffer layers (SiC/Si) by the direct deposition of carbon atoms using molecular beam epitaxy (MBE) equipment. The structural properties of the samples produced at different substrate temperatures (800, 900, 1000, 1100 ° C) were investigated by reflection high energy electron diffraction (RHEED), Raman spectroscopy and near-edge X-ray absorption fine structure (NEXAFS). The results indicate that the thin films grown at all temperatures exhibit the characteristics of graphene with a turbostratic stacking structure. As the substrate temperature increases the crystalline quality of the graphene improves. However, a very high temperature decreases the quality of graphene. The best graphene films were obtained at a substrate temperature of 1000 ° C. This is due to the low substrate temperature resulting in a too low carbon atom activity for the formation of an ordered six-member ring of C-sp2. When the substrate temperature was too high the silicon atoms in the substrate became so active that silicon atoms diffused to the surface of the sample through SiC buffer defects and they bonded to the depositing carbon atoms, which resulted in a lower crystallization quality of the carbon layers. © Editorial office of Acta Physico-Chimica Sinica.

Loading Hefei IRICO Epilight Technology Co. collaborators
Loading Hefei IRICO Epilight Technology Co. collaborators