Application Of Filtered Cathode Vapor Arc Deposition Technique In Preparation Of Solar Reflective Film Materials With High Reflectance

Solar energy is one of the most focused renewable energies. Its application is always theworldwide hottest research point. Solar thermal electricity technology is one of themainstream solar energy application methods. But its efficiency is still locked by its keycomponent solar collector. The research of solar collector has been conducted more than onehundred years. One of the key factors restricted its collecting efficiency to be improved is theaccuracy control of the reflector facets. The reflective film material with excellent formabilityand high reflectance is a good solution to this problem.As a film preparation technology widely used to prepare high precision films, filteredcathode vapor arc deposition technology (FCVAD) has an advantage of uniform film formingarticles and high energy deposition compared to other film preparation technologies. The filmdeposited by FCVAD always has good film quality and high film adhesion. In this paper,FCVAD was innovatively introduced to prepare solar reflective film materials with highreflectance. Aluminum films of nanometer grade were deposited on glass substrate and PETsubstrate respectively. UV-VIS-NIR spectrophotometer, SEM, step profiler and pull-offadhesion tester were employed to investigate the reflectivity, surface morphology, spatialstructure, film thickness and film adhesion of reflective materials prepared. The influence ofFCVAD parameters such as arc current, negative bias, duty cycle and deposition numbers onfilm thickness and reflectivity was focused.The thickness and reflectivity of Aluminum film were turned out to be mainly influencedby arc current, negative bias, duty cycle and deposition numbers when the substrate is glass.There was a linear positive correlation between Aluminum film thickness and depositionnumbers, and a positive correlation between Aluminum film thickness and arc current, and anegative correlation between Aluminum film thickness and negative bias or duty cycle. Theseinfluences were mainly generated by the changes of film forming article size, spatial structurecompactness and surface alignment which were caused by these factors changes. The relationbetween Aluminum film reflectivity and deposition numbers matched the software simulationresults. The Aluminum film reflectance increased rapidly with the increase of negative bias atthe beginning, and maintained the maximum reflectance for a while when the negative bias increased to a critical value, then decreased again with the increase of negative bias. Theinfluence of arc current on Aluminum film reflectance was not significantly. The reflectanceincreased rapidly with the increase of arc current in an entirely short range when the arccurrent was low, and turned to maintain a maximum reflectance in the following arc currentrange. The Aluminum film reflectance showed an oscillating drop with the increase of dutycycle. These effects were mainly produced by the changes of the average film formingparticle size, spatial structure compactness, surface uniformity, surface defects, effective filmoptical thickness and optical parameters which were caused by those factors changes. And thefilm adhesion of this reflective film material met the practical requirement completely.Compared to magnetron sputtering technology, FCVAD had more advantages in preparingreflective film.Finally, Aluminum film was deposited on PET by FCVAD after ion implantation and ionmixing surface treatment, in order to explore the preparation of flexible solar reflective filmmaterials which was based on polymers and equipped with high reflectance. The influenceof this surface treatment on the reflective film reflectivity and film adhesion wasinvestigated also.