Ultra-short pulsed laser radiation applied on silicon decreases the reflectivity by modifying the surface topology by ablation to achieve a so called “black silicon” texture. A multitude of laser processing parameters are investigated in order to classify the reflectivity reduction. Exemplarily, 5-inch mc-silicon solar wafers are machined in a first step with high throughput using a linear 7-foci diffractive optical element (DOE). In a second step, solar cells are built up to determine the efficiency gain by the laser surface modification. A preliminary absolute efficiency gain of Δη > 0.2 \% is achieved at an absolute reflectivity reduction of globally 11.2 \% in comparison to a conventional isotexture.