Preparation And Light Trapping Properties Research Of Carbon Nanotube Arrays Based On Photovoltaic

In this paper, carbon nanotube arrays(CNTs) film was prepared by thermal chemical vapor deposition(TCVD) method in monocrystalline silicon substrate which deposited nickel particles as catalyst. Scanning electron microscope(SEM) and transmission electron microscope(TEM) were used to characterize the morphology and structure of carbon nanotubes. Effects of catalyst, the flow of carbon source gas and growth time on the processing of carbon nanotubes prepared by TCVD were discussed. The formation mechanism of CNTs were also analyzed, light trapping properties of CNTs was studied at the end.Spin coating transfer method and magnetron sputtering method were used to prepare catalysts in experiment. Spin coating transfer method which utilize PS microspheres was used to fabricate patterned catalyst and magnetron sputtering method could be used to prepare catalyst with uniform and controllable thickness through the SEM results. The catalyst particles were easy reunited at high temperature and the suitable thickness were5-10 nm by study the effect of catalyst in the growth of CNTs. Effects of different flow of carbon source gas and growth time were studied, the diameter and length of carbon nanotubes will be larger with greater acetylene flow and long growth time, but the carbon nanotubes could not be prepared when the acetylene flow exceed 70 sccm or the grow time over 20 min.Decomposition products of acetylene in different areas under single temperature zone heating conditions have been researched, carbon nanotubes and spherical carbon which have different morphology were prepared under the condition of temperature gradient, the formation mechanism of spherical carbon was analyzed.Ni/copper net, Ni(NO3)2/Cu(NO3)2 and Ni(NO3)2/Fe(NO3)3 were used as the composite catalysts to catalytic pyrolysis the acetylene, different structure of helical carbon fiber were prepared and their growth mechanism were also discussed.Light trapping properties of CNTs film and traditional silicon-based solar cells structure were studied by ultraviolet-visible spectrophotometry, the reflectance of CNTs film was about 5% in 200-800 nm UV-visible wavelengths, which is more effective than monocrystalline and polycrystalline cell surface structure, the principle of light trapping was studied at the end.