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We fabricated large area bilayer graphene by hot filament chemical vapor deposition (HFCVD) on Cu foil. The HFCVD technique can represent a significant advantage over other techniques for industrial scaling at low cost. We performed systematic experiments to determine the best parameters to obtain uniform graphene coverage over an area of ~ 16 cm 2 . The experimental growth parameters are grouped into two distinct regions according to the products obtained: (A) continuous bilayer graphene with low defect density and (B) continuous bilayer graphene with high defect density. The optimum graphene films obtained are uniform bilayer with low defect density, greater than 90% transmittance in the visible region, and no gaps. The high quality of the bilayer graphene was confirmed by Raman spectroscopy mapping. The results show that the ratio of 2D to G peak intensities ( I 2D / I G ) is in the 0.9–1.6 range over 90% of the area. Moreover, we employed the static cling property of polyethylene terephthalate (PET) to preserve the integrity of the as-grown graphene films in the transfer process, showing that the graphene films become well attached to the SiO 2 /Si substrates while the PET films were completely peeled off. [ABSTRACT FROM AUTHOR]

Abstract: Carbon nanotubes (CNTs) have been fabricated on free-standing microcrystalline diamond (FSD) films by hot filament chemical vapor deposition using Ni as catalyst. Micro Raman spectroscopy has been used as a primary technique to characterize the hybrid material, while electron microscopy and electron energy loss spectroscopy served as complementary characterization techniques. The fabricated material shows the presence of multiwall carbon nanotubes of diameters in the range of 10–15nm with a wall thickness of 5–6nm protruding from the free-standing microcrystalline diamond films of crystallite sizes ranging from 0.5 to 2.0μm. The CNT-FSD films show good field emission properties with low turn-on field, large field enhancement factor, and an excellent current stability over a period of 10days. [Copyright &y& Elsevier]

Abstract: Spontaneously detaching self-standing diamond films were successfully fabricated using saturated hydrocarbon polymers as seeding source by hot filament chemical vapor deposition (HFCVD) technique. X-ray diffraction confirmed the crystal structure of diamond. The microcrystalline morphology of the diamond films was analyzed by atomic force microscopy (AFM) and scanning electron microscopy. Raman spectra from the front and back sides of the films show the characteristic diamond band at 1332cm−1 and no carbide layer. EELS spectra also show the signature features of diamond. The use of hydrocarbon polymers as seeding source will improve the cost-effectiveness of the fabrication of diamond wafers by simplifying the fabrication process. [Copyright &y& Elsevier]