| CPC H10F 71/1221 (2025.01) [B23K 26/0624 (2015.10); B23K 26/0676 (2013.01); B23K 26/354 (2015.10); B23K 26/402 (2013.01); H10F 77/219 (2025.01); H10F 77/311 (2025.01); B23K 2101/40 (2018.08)] | 18 Claims |

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1. A preparation method of a solar cell, characterized in comprising:
forming a passivation structure on a contact silicon layer at a back side of a silicon substrate; wherein the back side is a side opposite to a light incident side;
removing the passivation structure located at least part of an electrode region by laser to form a contact opening, melting at least part of the contact silicon layer at the contact opening by laser, and solidifying the molten contact silicon layer to form a re-solidified structure; wherein the electrode region is a region configured to form a back electrode; and
electroplating to form the back electrode in the electrode region on the back side of the contact silicon layer,
characterized in that removing the passivation structure located at least part of the electrode region by laser to form the contact opening comprises:
irradiating the passivation structure at a plurality of spaced positions in the electrode region by laser, removing the irradiated passivation structure to form a contact opening, and tilting an edge portion of the remaining passivation structure close to the contact opening;
wherein the back electrode has a thickness greater than the passivation structure.
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