Direct Laser Texturing for High-Efficiency Silicon Solar Cells

Abstract

We implement direct laser texturing (DiLaT) into small-area (2 × 2 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) 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 <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sc</sub> up to 39.3 mA/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and efficiencies up to 17.9%. The reduced <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sc</sub> 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.