COMPOSITIONS AND PROCESSES FOR FABRICATION OF REAR PASSIVATED SOLAR CELLS

摘要

Compositions used in, and methods for, fabricating a rear-passivated silicon solar cell are described. A novel method of opening the back surface for contacting the silicon with a conventional aluminum paste is described. Various novel screen printable etch resists are described. First, such an etch resist can be printed on the rear of a rear-passivated solar cell wafer. The passivation layer can then be removed using a wet etch, and next the etch resist layer can be removed. Further, an additional wet etch step may optionally be used to deepen the opening into the silicon and enhance the BSF (back-surface field). Aluminum paste can then be printed over the entire backside of the now etched cell. The entire cell is then fired. In exemplary embodiments of the present invention, the paste can be chosen so that it will not fire through the passivation layer.

主权项

1. A composition of matter suitable for use as an etch or plating resist in a process for manufacturing passivated emitter rear contact (PERC) solar cells, comprising:
organic compounds comprising:
a phenol-formaldehyde resin; a vinyl polymer or copolymer; a vinyl acetate polymer or copolymer; a rosin resin or a modified rosin resin; a rosin polyester; a gum rosin or a modified ester of a gum rosin; shellac; melamine or modified melamine resin, cyclized rubber, Gilsonite® or uintahite resin or combinations thereof; one or more solvents; and a rheological modifier.