Solar cell and method for producing a solar cell

A solar cell comprising:

• a planar semiconductor substrate with a front and a back;
• a multitude of holes that interconnect the front and the back;
• and
• current-collecting electrical contacts that are exclusively arranged on the back;
• wherein
• the front comprises doping of a first type;
• the interior wall of the holes comprises doping of the first type or metallization;
• the back comprises first regions that comprise the holes and that comprise doping of the first type, as well as second regions that comprise doping of a second type;
• the current-collecting electrical contacts comprise first contacts that contact the first regions of the back, and second contacts that contact the second regions of the back;
• and
• the front comprises highly doped regions and lightly doped regions of the first type such that in each case the holes are situated in a highly doped region or adjoin such a region,
• wherein the highly doped regions are arranged locally around the holes, wherein the individual local, highly doped regions are spatially separated from each other.

A method for manufacturing a solar cell with the steps of:

• provision of a planar semiconductor substrate with a front and a back;
• application of a diffusion mask over the entire surface area, at least to the front;
• fabrication of a multitude of holes in the semiconductor substrate, which holes interconnect the front and the back;
• selective removal of the diffusion mask such that the diffusion mask is removed at least in the regions where the holes are located or to which the holes adjoin;
• carrying out strong diffusion with a dopant of a first type, wherein the regions of the front, in which regions the diffusion mask was selectively removed, is highly doped;
• complete removal of the diffusion mask at least from the front;
• carrying out light diffusion with a dopant of the first type.

A method for manufacturing a solar cell with the steps of:

• provision of a planar semiconductor substrate with a front and a back;
• provision of a multitude of holes in the semiconductor substrate which holes interconnect the front and the back;
• carrying out strong diffusion with a dopant of a first type at least on the front, wherein the entire front is highly doped;
• application of a diffusion mask over the entire surface area, at least to the front;
• selective removal of the diffusion mask such that the diffusion mask is left in place only in defined regions where the holes are located or to which the holes adjoin;
• followed by
• removal of the regions that are highly doped in strong diffusion in the regions of the front, which regions are located outside the diffusion mask;
• carrying out light diffusion with a dopant of the first type, at least on the front;
• and
• complete removal of the diffusion mask, at least from the front.