Effect of Nitrogen on the Growth of Carbon Nitride Thin Films Deposited by RF Plasma Enhanced Chemical Vapor Deposition

ABSTRACTCrystalline carbon nitride films have been synthesized in a rf plasma assisted hot filament chemical vapor deposition system. Large crystalline grains up to ∼10 μm in size as well as film-like regions are observed in the morphology of the films. β-C3N4 with two groups of lattice parameters ( one is consistent with the theoretical value and the other is 3% smaller) in the deposited films on polycrystalline Ni substrate has been revealed by x-ray diffraction spectrum (XRD). No Raman shift peaks have been found evidently by Raman scattering measurement, but some presently unknown diffraction peaks appeared in the XRD spectrum. It is proposed that there are possible unknown structures of crystalline C-N in the films. Heteroepitaxial growth of crystalline β-C3N4 has also been tried via a buffer layer of α-SiC on Si (100) substrate. The XRD pattern of a film show that there are only two main peaks at 2.79 Å and 1.87 Å corresponding to the (200) and (300) crystalline planes of the theoretical β-C3N4 The two main peaks indicate heteroepitaxial growth along the (100) direction of β-C3N4.

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MWCNTs - Ni-Cu NPs @ a-C:H thin films: Study of relation between the average diameters of CNTs with optical density and topological characterizations

10.21203/rs.3.rs-25789/v1 ◽

2020 ◽

Author(s):

Samira Goudarzi ◽

Vali Dalouji

Keyword(s):

Thin Film ◽

Thin Films ◽

Chemical Vapor Deposition ◽

Optical Density ◽

Vapor Deposition ◽

High Spatial Frequency ◽

Chemical Vapor ◽

High Energy ◽

Rf Plasma ◽

Minimum Value

Abstract In this paper, Ni-Cu NPs @ a-C:H thin films with different content of cooper by co-deposition of RF-sputtering and RF-plasma enhanced chemical vapor deposition (RF-PECVD) were prepared from acetylene gas and Ni and Cu targets. The prepared samples as catalysts for growing multi-wall carbon nanotubes (MWCNTs) were used from liquid petroleum gas (LPG) by thermal chemical vapor deposition (TCVD) at 825 °C. The films deposited with 5% Cu have minimum value the average diameter of CNTs and were about 100 nm. The fractal dimensions and structural characteristics as well as optical density of Ni-Cu NPs thin films have been investigated. AFM images can estimate the lateral size of the nanoparticles on the films surface. These values for Ni NPs without Cu NPs @ a-C:H thin film and with Cu NPs thin film contenting 5%, 40%, 75% Cu are obtained about 7.2, 5.34, 6.04 and 11.16 nm respectively. The optical density (Dopt) of thin films was obtained from the relation Dopt = \alpha t. Films deposited with 75% Cu have maximum value of optical density specially in high energy. The spectral density power of all layers reflects the reverse flow changes,, especially in the high spatial frequency region, indicating the presence of fractal components in prominent topographies. Films deposited with 75% Cu have minimum value of fractal dimension. The diagram of the Bearing Area proportion the height shows the percentage of cavities and single-layers. It can be seen that the single-layer content of all films were about 95%.

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