Extending the limits of laser beam shaping for pv-cell manufacturing

Laser processing of photovoltaic cells enables the manufacturing of high-efficiency cells and offers opportunities to cut down costs. Structuring of selective emitters or laser fired contacts requires precise laser beam shaping. In this paper we identify key design parameters for industrial applications of Gaussian-to-top hat converters. We derive the physical limits for top hats close to the diffraction limited and compare the performance of actual beam shapers to these limits. Additionally we present details and first measurements of our improved solution to scan a 50 mu m top hat, allowing to structure a 156mm wafer in a few seconds.