Laser surface texturing for reducing reflection losses in multicristalline silicon solar cells

We investigate two laser processes for surface texturing of silicon solar cells. One uses direct laser ablation of Si of the as-cut wafers without any masking technique. The other process structures a dielectric layer that is subsequently used as an etching mask. Both texturing processes combine laser structuring and wet chemical etching. Besides a spot-wise scanning process using a solid state laser system that features a galvo scanner, also an imaging technique based on an excimer laser is applied. With both approaches we achieve a homogeneous, honeycomb-like texture on the silicon wafer surface. The approach with the excimer laser is economically more attractive due to a substantially higher throughput.