Increasing the Efficiency of Screen-Printed Silicon Solar Cells by Light-Induced Silver Plating

Abstract

This paper presents a method to improve the efficiency of large area screen-printed silicon solar cells by about 0.3% to 0.4% absolute. By light-induced plating (LIP) the series resistance of screen-printed solar cells is reduced. The line conductivity of the front side metal conductors is improved without increasing the shaded area. This plating technique has been optimized for years at Fraunhofer ISE and is a fast method to homogeneously galvanize metal contacts on n-doped material. High efficiencies of 18.4% on 20x20 mm2 screen-printed FZ silicon solar cells and 16.6% on 156x156 mm2 industrial processed mc-Si solar cells have been obtained. It is believed that the significant increase of efficiency combined with the reduction of the amount of screen-printing paste required, overcompensates the cost for this additional step at the end of the process sequence.