Laser assisted honeycomb-texturing on multicrystalline silicon for industrial applications

In this study we investigated a manufacturing process for Honeycomb-texturing. An optimized masking dielectric layer, the opening of the mask via laser and an industrially applicable under-etching process lead to a homogeneous hexagonal structure with etch holes of 15 µm depth and a width of 31.5 µm. The reflection is dependent on the honeycomb structure or the surface roughness. It has been shown that by a short etching time the honeycomb texture is not completed, the surface is covered with too small honeycomb cavities; the unetched surface contributes with a reflection of 23 % to an increased total reflection at the surface. An optimum by etching time of 78 s (minimum reflection) was achieved, with a honeycomb width Wd = 31.5 µm and a depth honeycomb Wh = 15 µm, which lead to the best reflection of 17.5 % and even the highest lifetime of 604 ìs after passivation.