Method for the contact separation of electrically-conducting layers on the back contacts of solar cells and corresponding solar cells

摘要

A method for fabricating a solar cell ( 1 ) comprising a semiconductor substrate ( 2 ) is proposed where electrical contacting is made on the back side of the semiconductor substrate. The back side of the semiconductor substrate has locally doped regions ( 3 ). The adjacent regions ( 4 ) exhibit different doping from the region ( 3 ). The two regions ( 3, 4 ) are initially coated with electrically conductive material ( 5 ) over the entire area. So that the conductive material ( 5 ) does not short-circuit the solar cell, the two regions ( 3, 4 ) are covered with a thin electrically insulating layer ( 7 ) at least at the region boundaries ( 6 ). The electrically conductive layer ( 5 ) is separated by applying an etch barrier layer ( 8 ) over the entire surface which is then removed free from masking and selectively e.g. by laser ablation, locally above the insulating layer ( 7 ). The conductive layer is locally removed in the area of the openings ( 9 ) of the etch barrier layer ( 8 ) by subsequent action of an etching solution.