Product Code: ICA11_M306

Patterning and Marking of Textured and Untextured Silicon Solar Cells using a 532 Nm Picosecond Fiber Laser
Authors:
Tim D. Gerke, Fianium Inc.; Eugene OR USA
Brian Baird, Summit Photonics; Lake Oswego OR USA
Presented at ICALEO 2011

Laser microprocessing is key to the development and manufacture of advanced silicon photovoltaics. In this paper a picosecond laser is used to pattern and mark the surface of both textured and non-textured passivated silicon photovoltaics as well as unpassivated silicon wafers. The laser is a master oscillator fiber power amplifier that provides 30 picosecond pulses at 532 nm with pulse energy up to 5 micro-Joules. We evaluate and compare techniques for marking and patterning crystalline-silicon substrates utilizing a conventional Gaussian beam and a flat-top spatially-shaped square beam. We show that SiOx and SiNx passivation layers on both textured and non-textured crystalline-silicon photovoltaics can be removed in arbitrary patterns. We demonstrate that not only can the passivation layers be removed, but the surface of either passivated and unpassivated silicon substrates can be marked in a continuum of shades of gray and in arbitrary patterns. These results demonstrate the promising capability for advanced patterning and marking of photovoltaic devices and for marking of silicon wafers with picosecond fiber lasers.