| 以上两项分析数据表明，如果在EVA内部有足够的水分，就会导致乙酸离子性杂质的形成，也就会形成腐蚀。道康宁有机硅封装材料在湿热条件下，不仅平衡点的水分吸收比EVA材料低一个数量级，其降解机制或固化体系的副产品中没有离子杂质。从腐蚀三角形的观点来看，有机硅封装材料比EVA更能减少腐蚀的肯能行。
5. 结论
在EVA封装的情况下，液态水分和离子物质可能并存在封装材料和金属的界面，而有机硅具有更低水分含量，没有离子物质的形成。可以推论EVA比有机硅提供了更有腐蚀性的环境，即使硅胶的水蒸气透过率WVTR比EVA的显著较高。腐蚀环境在理论上讲就是EVA组件暴露在长时间湿热老化环境后衰减的原因所在。这里讨论的组件为多晶硅和单晶硅电池组件，当暴露在湿热条件后，单晶EVA组件经过1500小时、多晶EVA组件经过3500小时，功率衰减都超过IEC的限值5％。而已经硅封装的组件在单晶组件2000小时DH，多晶组件3500小时的DH后，性能上几乎没有变化。数据的进一步分析表明，这种衰减与填充因子降低及串联电阻增加相关，都与腐蚀增加有关。
6. 参考文献
[1] Polymeric Materials Encyclopedia, Volume 4, edited by Joseph C. Salamone
[2] Sierawski, David A.; Currin, C.G.; The Use Of Silicone Gel For Potting Photovoltaic Arrays, Proceedings of the International Solar Energy Society, Orlando, FL, June 1977.
[3] Willis, P.B., Baum, B.; Investigation of Test Methods, Material Properties, and Processes For Solar Cell Encapsulants, Annual Report JPL Contract 954527, Springborn Laboratories, INC. Enfield, Connecticut 06082, June 1979
[4] Tonge, J. S. Lane, T. H. Agbomeirele, P. A. Giwa; Klimisch, H. M. Sil-bar: silicone corrosion barrier. Proc. - Electrochem. Soc. (1989) 89-13(Proc. Symp. Adv. Corros. Prot. Ogr. Coat.) 151-9
[5] Mancke, R.G.; A Moisture Protection Screening Test for Hybrid Circuit Encapsulants, Proceedings of 31st Electronic Components Conference, April 1981, pp 119-125
[6] Leidheiser, H; Corrosion Control by Coatings, 1979 Science Press, pp.29-34 and pp.35-45.
[7] White, M.; The Encapsulation of Integrated Circuits, Proceedings of IEEE, Volume 57, No. 9, September 1969.
[8] Fontana, Mars G.; Corrosion Engineering, 3rd edition, McGraw-Hill, New York, 1986.
[9] Kempe, M.D.; Control of Moisture Ingress into Photovoltaic Modules, 31st IEEE Photovoltaics Specialists Conference and Exhibition Lake Buena Vista, Florida January 3–7, 2005
[10] Hacke, P. & Meier, D.L.; Analysis of Fill Factor Losses Using Current-Voltage Curves Obtained Under Dark and Illuminated Conditions, Proceedings of IEEE, 2002.
全文完。 | 
