Solar cell and preparation method thereof

The invention relates to a solar cell and a preparation method thereof. The preparation method of the solar cell comprises the following steps: preparing a first doped silicon material layer, a first intrinsic silicon material layer and a first protective layer which are sequentially stacked on the surface of a substrate; a groove is formed in the first protection layer through laser, the groove only penetrates through the first protection layer, or the groove penetrates through the first protection layer and partially penetrates through the first intrinsic silicon material layer; etching to remove the first doped silicon material layer at the groove; and annealing to convert the first doped silicon material layer and the first intrinsic silicon material layer into a first doped polycrystalline silicon layer. According to the preparation method of the solar cell, the laser does not make contact with the doped silicon material layer, formation of a local highly-doped region in the laser grooving process is red