电化学机械复合抛光薄膜太阳能电池柔性不锈钢衬底

设计了针对薄膜太阳能电池柔性不锈钢衬底的电化学机械复合抛光法以满足其对表面粗糙度、光反射率和有害物质扩散的要求。首先,设计并制造了一种用于平面加工的复合阴极刀具,理论分析了它的材料去除机理。然后,结合法拉第原理和黏着摩擦理论分析了电化学腐蚀行为和摩擦力作用行为,解决了电化学腐蚀和机械去除钝化膜的匹配一致性问题。最后,以50mm×50mm×0.3mm规格的304不锈钢为阳极工件,对提出的方法进行了实验验证。结果显示:对衬底加工20min后,其表面粗糙度Ra从124nm降到10nm;表面反射率从加工前的56.8%提高到62.4%;表面金属氧化层的形成(氧化铁和氧化铬),有效阻挡了Fe和Cr离子的扩散。实验显示,提出的方法是处理柔性不锈钢表面的有效方法,成本低、效率高。

Electrochemical mechanical polishing of thin film solar cell flexible stainless steel substrate

A novel method integrating electrochemical machining with mechanical action was proposed to polish the flexible metal foil to satisfy the requirements of thin-film solar cell flexible stainless steel substrate for lower surface roughness,higher light reflection rate and lower harmful impurity. Firstly,a compound cathode was designed and manufactured for machining flat surfaces,meanwhile its mechanism on the material removal was analyzed. Then,the electrochemical corrosion behaviors and friction effects were analyzed based on the Faraday law and adhesion friction theory, by which the match action between electrochemical corrosion and mechanical action was resolved. Finally,taking the 304 stainless steel sized 50 mm×50 mm×0.3 mm as the workpiece,an experiment was conducted to demonstrate above analysis. The results show that the surface roughness has changed from R_a124 nm to R_a10 nm and the reflection rate changed from 56.8% to 62.4% after polishing time of 20 min. Moreover, a metal oxide layer(Fe₂O₃,Cr₂O₃) is formed, which blocks the diffusion of Fe and Cr. These results indicate that the method proposed has higher efficient and economical to process thin film solar cells with flexible stainless steel foils.