Back contact solar cell and method for preparing same, and battery assembly

A method for preparing a back contact solar cell, comprising:

• providing a semiconductor substrate, the semiconductor substrate having a light receiving surface and a shady surface that are opposite to each other, the shady surface comprising a first polarity region and a second polarity region arranged alternately in a first direction;
• forming a first functional layer in the first polarity region, the first functional layer comprising a first passivation layer and a first doped semiconductor layer that are stacked in a direction away from the semiconductor substrate;
• forming a second functional layer in the second polarity region, the second functional layer comprising a second passivation layer and a second doped semiconductor layer that are stacked in a direction away from the semiconductor substrate, the first doped semiconductor layer having a doping type opposite to a doping type of the second doped semiconductor layer;
• forming a laser protection layer on a side of the second functional layer away from the semiconductor substrate, the laser protection layer comprising a laser absorption material;
• removing a part of a film layer corresponding to an electrode contact region of the first functional layer on a side of the first functional layer away from the semiconductor substrate and a part of a film layer corresponding to an electrode contact region of the second functional layer on the side of the second functional layer away from the semiconductor substrate to expose the electrode contact regions;
• and
• forming an electrode structure in each of the electrode contact region of the first functional layer and the electrode contact region of the second functional layer,
• wherein forming the first functional layer in the first polarity region comprises forming a doped substrate layer located in the first polarity region and in direct contact with the first passivation layer, the doped substrate layer having a same doping type as the first doped semiconductor layer, wherein a surface of the doped substrate layer close to the first passivation layer is a polished surface, and the doped substrate layer is in direct contact with the second passivation layer formed in the second polarity region in the first direction.