Papers by Keyword: Amorphous Carbon Films

Abstract: Hydrogenated amorphous carbon (a-C:H) films were prepared by microwave plasma chemical vapor deposition (MW-PCVD) technique with a mixture of acetylene and hydrogen. The morphology of three-phase a-C:H films, such as graphite-like, diamond-like and polymer-like were modulated by microwave power, deposition pressure, and flow ratios. Meanwhile, annealing does not seem to change the surface morphology or the film structure. The phase transitions are not found during the different annealing temperatures, showing that a-C:H films have a good thermal stability.

Abstract: Graphite-amorphous carbon films were grown by sputtered Ni target in Ar/CH4 mixture atmosphere. The impacts of N2 import into reaction system on the structures and properties of the graphite-amorphous carbon films were studied. The results shown that graphite-amorphous carbon films with good hardness, elastic and friction coefficient were obtained at the N2/CH4 flow ratio below 20/80. Beyond the flow ratio of 20/80, the number and size of nanocrystal graphite decrease induce the bad hardness, elastic and friction coefficient of the graphite-amorphous films. Graphite-amorphous carbon films properties were possible correlate with the size and number of nanocrytal graphite and its crosslinking degree to carbon network, especially the former.

Abstract: This paper studied the impact of silicon oxide layer on photovoltaic characteristic of iron-doped amorphous carbon film/silicon heterojunction (a-C:Fe/Si). The results show that a native SiO2 layer on the silicon surface can provide a significant improvement of the a-C:Fe/Si devices’ photovoltaic performances, especially for the short circuit current and fill factor. This improvement partly may be attributed to the electron recombination process is suppressed and the interface is modified by the SiO2 film based on the open circuit voltage decay measurement.