TOPCon battery structure

The utility model discloses a TOPCon cell structure, comprising a silicon substrate, the back surface of the silicon substrate is provided with a phosphorus diffusion doping layer, the phosphorus diffusion doping layer is provided with latticed patterns comprising a tunneling oxide layer and a phosphorus-doped polycrystalline silicon layer from inside to outside in sequence, the surfaces of the phosphorus diffusion doping layer and the phosphorus-doped polycrystalline silicon layer are covered with a back passivation layer, and the back passivation layer is covered with a back passivation layer. The back surface of the silicon substrate is also provided with back surface grid lines, the back surface grid lines penetrate through the back surface passivation layer to form ohmic contact with the phosphorus-doped polycrystalline silicon layer, and the pattern shape of the back surface grid lines on the back surface of the silicon substrate is the same as the latticed pattern. According to the TOPCon battery struc