Transport and optical properties of amorphous carbon and hydrogenated amorphous carbon films

Density and localized states' impact on amorphous carbon electron transport mechanisms

“…Thus, here, we used DFT-NEGF to investigate the electron transport mechanisms in ultra-small a-C structures, analyzing the effects of density, dimensionality, and contact with metallic electrodes. We were able to explain different types of conductions observed experimentally: 7,26,27 semimetallic in lowdensity a-C films, and thermally activated for sp 3 rich a-C. Our calculations also support experimental evidence of resonant tunneling (RT) in ultra-thin films, 1,11,12 and establish three regimes of dominant mechanisms, as a function of the density.…”

“…The slope changes as the voltage increases, which is a common feature in systems whose dominant transport mechanism is thermally activated. 27,62 These results are only qualitative, since a SZP basis set is unable to represent accurately the energetics of a-C, especially in high-density samples, as shown in previous works. 32,33 Therefore, we calculated the I-V curves for a set of samples with densities ranging from 2.23 to 3.20 g/cm 3 , using a DZP basis set, as shown in Fig.…”

Low resistive diamond like carbon film development technique

“…Yet, the various nitrogen forms and their interrelations in plasma have not been covered in literature consistently [6][7][8]. Partly this is the reason that data referred in literature sometimes are contradictory [11][12][13].…”

“…Actually, required properties of the films obtained by this method could easily be varied by changing the deposition parameters. The properties of coatings could be modified either by dopants [6][7][8] or structurally via the variation of technological parameters, i.e. power of ion source, voltage applied to substrate, availability of additional electric or magnetic fields, process geometry changes, etc.…”

Tribological properties of amorphous hydrogenated (a-C:H) and hydrogen-free tetrahedral (ta-C) diamond-like carbon coatings under jatropha biodegradable lubricating oil at different temperatures

“…It has been extensively applied in optics, mechanics, electronics (such as piezoresistivity [9]), and biomedicine [10]. This compound exhibits good anti-wear properties, low friction, extreme hardness, and excellent corrosion resistance [11].…”