Direct Laser Texturing for High-Efficiency Silicon Solar Cells

We implement direct laser texturing (DiLaT) into small-area (2 × 2 cm ²) passivated emitter and rear solar cells (PERC). On monocrystalline float-zone silicon (FZ-Si) wafers, we achieve an independently confirmed energy conversion efficiency of 19.9% that demonstrates the applicability of DiLaT to high-efficiency solar cells. Applying our DiLaT process to block-cast multicrystalline silicon (mc-Si) wafers, we achieve short-circuit current densities J_sc up to 39.3 mA/cm² and efficiencies up to 17.9%. The reduced J_sc value of our mc-Si solar cells compared with the FZ-Si cells is shown to be predominantly due to increased recombination in the bulk and/or the rear.