New Emitter Design and Metal Contact for Screen-Printed Solar Cell Front Surfaces

Abstract

A new emitter design incorporating semiconductor fingers has been developed for use with conventional screen-printing technology. The primary advantage of this new design is that it alleviates the need for a heavy top surface diffusion and therefore overcomes the major weaknesses traditionally associated with screen-printed solar cells, namely a poor response to short wavelengths of light and a high top surface metal shading loss. Importantly, the new technology is compatible with all existing screen-printing equipment and infrastructure. Direct comparison between conventional screen-printed cells and those incorporating semiconductor fingers shows the latter to have about a 10% performance advantage when fabricated on a large scale manufacturer's production line. Efficiencies about 18% have been demonstrated on 150cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> devices with the new technology planned for large scale manufacturing by the end of 2006