Dielectric function, electronic properties and optical constants of amorphous carbon and carbon nitride films

Gioti, M.; Logothetidis, S.

doi:10.1016/s0925-9635(02)00222-4

Cited by 54 publications

(42 citation statements)

References 19 publications

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“…The resonance energy for π→π* electronic transitions for crystalline graphite is found at 4.5 eV but the energy decreases when the amount of sp 2 -clusters in the matrix increases [36] or when the sp 2 sites exhibit a different arrangement [19]. This is in agreement with the lower resonance energies noticed for these films, located between 31000-32450 cm -1 (3.8 and 4.0 eV), where the lowest energy is observed for the g-CN x film (G8) and the highest for the FL-CN x film (F9) [19,37]. The strongest peak for the π→π* transition is noticed for the a-C film (C8) [19] and the weakest for the FL-CN x film, which might be explained by a higher disorder in the sp 2 matrix for the FL and graphitic films which reduces the conjugation of the π electrons [13].…”

Section: Range 31000-32450 CM -1 (38-40 Ev) → *supporting

confidence: 84%

Spectroscopic ellipsometry characterization of amorphous carbon and amorphous, graphitic and fullerene-like carbon nitride thin films

et al. 2009

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Section: Range 31000-32450 CM -1 (38-40 Ev) → *supporting

confidence: 84%

Spectroscopic ellipsometry characterization of amorphous carbon and amorphous, graphitic and fullerene-like carbon nitride thin films

et al. 2009

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“…The TL dispersion model is also widely used for modelling the optical dispersion of a-C, a-C: H [44] as well as polycrystalline diamond films [45]. The model is a combination of the Tauc joint density of states [42] and the quantum-mechanical Lorentz oscillator model [46]. The TL model fits to the dielectric functions of a class of an amorphous material.…”

Section: Spectroscopic Ellipsometry Measurement Systemmentioning

confidence: 99%

Characterization of Optical and Electrical Properties of Transparent Conductive Boron-Doped Diamond thin Films Grown on Fused Silica

Bogdanowicz¹

2014

Metrology and Measurement Systems

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A conductive boron-doped diamond (BDD) grown on a fused silica/quartz has been investigated. Diamond thin films were deposited by the microwave plasma enhanced chemical vapor deposition (MW PECVD). The main parameters of the BDD synthesis, i.e. the methane admixture and the substrate temperature were investigated in detail. Preliminary studies of optical properties were performed to qualify an optimal CVD synthesis and film parameters for optical sensing applications. The SEM micro-images showed the homogenous, continuous and polycrystalline surface morphology; the mean grain size was within the range of 100-250 nm. The fabricated conductive boron-doped diamond thin films displayed the resistivity below 500 mOhm cm -1 and the transmittance over 50% in the VIS-NIR wavelength range. The studies of optical constants were performed using the spectroscopic ellipsometry for the wavelength range between 260 and 820 nm. A detailed error analysis of the ellipsometric system and optical modelling estimation has been provided. The refractive index values at the 550 nm wavelength were high and varied between 2.24 and 2.35 depending on the percentage content of methane and the temperature of deposition.

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“…Such approach has been recently applied by Zimmer et al [42] for boron-doped NCD films, Hu et al [15] for MCD films, and Jellison et al [43] for amorphous semiconductors. The model is a combination of the Tauc joint density of states [44] and the quantum mechanical Lorentz oscillator model [45]. The TL model fits to the dielectric functions of a class of amorphous materials.…”

Section: Diamond Growth On Fibresmentioning

confidence: 99%

Optical and structural properties of polycrystalline CVD diamond films grown on fused silica optical fibres pre-treated by high-power sonication seeding

et al. 2014

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In this paper, the growth of polycrystalline chemical vapour deposition (CVD) diamond thin films on fused silica optical fibres has been investigated. The research results show that the effective substrate seeding process can lower defect nucleation, and it simultaneously increases surface encapsulation. However, the growth process on glass requires high seeding density. The effects of suspension type and ultrasonic power were the specific objects of investigation. In order to increase the diamond density, glass substrates were seeded using a high-power sonication process. The highest applied power of sonotrode reached 72 W during the performed experiments. The two, most common diamond seeding suspensions were used, i.e. detonation nanodiamond dispersed in (a) dimethyl sulfoxide and (b) deionised water. The CVD diamond nucleation and growth processes were performed using microwave plasma assisted chemical vapour deposition system. Next, the seeding efficiency was determined and compared using the numerical analysis of scanning electron microscopy images. The molecular composition of nucleated diamond was examined with micro-Raman spectroscopy. The sp 3 / sp 2 band ratio was calculated using Raman spectra deconvolution method. Thickness, roughness, and optical properties of the nanodiamond films in UV-vis wavelength range were investigated by means of spectroscopic ellipsometry. It has been demonstrated that the high-power sonication process can improve the seeding efficiency on glass substrates. However, it can also cause significant erosion defects at the fibre surface. We believe that the proposed growth method can be effectively applied to manufacture the novel optical fibre sensors. Due to high chemical and mechanical resistance of CVD diamond films, deposition of such films on the sensors is highly desirable. This method enables omitting the deposition of an additional adhesion interlayer at the glass-nanocrystalline interface, and thus potentially increases transmittance of the optical system.

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Dielectric function, electronic properties and optical constants of amorphous carbon and carbon nitride films

Cited by 54 publications

References 19 publications

Spectroscopic ellipsometry characterization of amorphous carbon and amorphous, graphitic and fullerene-like carbon nitride thin films

Spectroscopic ellipsometry characterization of amorphous carbon and amorphous, graphitic and fullerene-like carbon nitride thin films

Characterization of Optical and Electrical Properties of Transparent Conductive Boron-Doped Diamond thin Films Grown on Fused Silica

Optical and structural properties of polycrystalline CVD diamond films grown on fused silica optical fibres pre-treated by high-power sonication seeding

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