Effect of Oxidizability on Texturization of Si Solar Cells

During the fabrication process of single crystal silicon(c-Si) solar cell,the anisotropic etching is often used to form a pyramidal structure on the c-Si wafer.This structure could reduce the reflection of light and enhance the efficiency of solar cells.It is clear that wafers with small and uniform pyramids on their surfaces are beneficial to improve the device performance.The texturing technique of sodium hypochlorite(NaClO) was optimized and a textured surface was obtained on which the average size of pyramids is 1.4 μm and the average reflectivity is 11.5%.The mechanism of texturization by NaClO was studied.The small pyramids formed by NaClO solution may own to the oxidizing property of NaClO.In order to investigate the effect of oxidizability on the process of texturization,oxygen gas and argon gas was flowed into the non-oxidizing NaOH solution,respectively.The results showed that adding oxidant in NaOH solution is effective to reduce the size of pyramids on the textured surface.As a alkaline and oxidizing reagent,NaClO does not need to add an extra oxidant in the texturing solution.Compared with the common texturing technique in NaOH solution,texturization in NaClO solution is easier to obtain a small and uniform pyramidal structure and is more suitable for the production of solar cells.