Topcon solar cell, cell assembly, and photovoltaic system

A Topcon solar cell, comprising:

• a silicon substrate having a first surface and a second surface, opposite to each other;
• a first tunneling oxide layer, a first polarity doped layer, and a first passivation layer sequentially stacked on the first surface;
• a second polarity doped layer and a second passivation layer sequentially stacked on the second surface, wherein a polarity of the second polarity doped layer is opposite to that of the first polarity doped layer;
• and
• a first metal electrode and a second metal electrode, wherein the first metal electrode is arranged on the first passivation layer, and the second metal electrode is arranged on the second passivation layer;
• wherein in an extension direction of the first metal electrode, a plurality of first barrier isolation layers arranged at intervals are located below the first metal electrode, the first barrier isolation layer is located between the first passivation layer and the first polarity doped layer, and the first metal electrode is made of a burn-through paste;
• at a position corresponding to the first barrier isolation layer, the first metal electrode burns through the first passivation layer to be in contact with the first barrier isolation layer, and between two adjacent first barrier isolation layers, the first metal electrode burns through the first passivation layer to be in contact with the first polarity doped layer, and the second metal electrode at least partially penetrates through the second passivation layer to be in contact with the second polarity doped layer;
• and
• the first barrier isolation layer is obtained by partially removing a wrap plating layer formed on the first polarity doped layer in the process of forming the second polarity doped layer.