P-TYPE BIFACIAL SOLAR CELL WITH PARTIAL REAR SURFACE FIELD PASSIVATION AND PREPARATION METHOD THEREFOR

摘要

The present application belongs to the technical field of solar cells, and relates to a p-type bifacial solar cell with partial rear surface field passivation and a preparation method therefor. The solar cell comprises a p-type silicon substrate (4). At the bottom portion of the p-type silicon substrate (4) are arranged, from top to bottom, a silicon oxide passivation layer (6), an aluminum oxide passivation layer (7) and a rear side silicon nitride anti-reflection layer (8). A plurality of boron source-doped layers (5) are embedded in the bottom portion of the p-type silicon substrate (4). Connected to the bottom of each of the boron source-doped layers (5) is a rear side metal electrode layer (9), which penetrates each of the silicon oxide passivation layer (6), the aluminum oxide passivation layer (7) and the rear side silicon nitride anti-reflection layer (8). The preparation method involves making a plurality of partial slots, by means of a laser, from the lower surface of the rear side silicon nitride anti-reflection layer (8) all the way to the bottom of the p-type silicon substrate (4), and printing a boron source slurry into the slot region to form a high-low junction structure. The high-low junction structure increases the open-circuit voltage of a rear side cell of the bifacial solar cell. The slot region heavily doped with the boron source slurry is in contact with the metal electrode to form an ohmic contact, which results in a decrease in series resistance and an increase in fill factor, and increases the bifaciality of the cell without decreasing efficiency on the front side.