Heterojunction solar cell and manufacturing method thereof, and photovoltaic module

A heterojunction solar cell, comprising:

• a substrate of a first conductivity type;
• a tunnel layer located on a light-receiving surface of the substrate;
• a doped polysilicon layer located on a surface of the tunnel layer away from the substrate, the doped polysilicon layer having the first conductivity type;
• a passivation anti-reflection layer located on the doped polysilicon layer;
• a first electrode penetrating through the passivation anti-reflection layer and electrically connected to the doped polysilicon layer;
• and
• a front surface field layer located on the light-receiving surface, the front surface field layer having the first conductivity type;
• wherein the first electrode includes:
• a lead-out electrode extending from a surface of the passivation anti-reflection layer away from the substrate into the passivation anti-reflection layer;
• and
• a contact layer, a surface of the contact layer away from the substrate being in contact with a surface of the lead-out electrode adjacent to the substrate, and a surface of the contact layer adjacent to the substrate being in contact with the doped polysilicon layer;
• and
• wherein the contact layer includes:
• a first sub-contact layer located between the lead-out electrode and the doped polysilicon layer;
• and
• a second sub-contact layer located on the surface of the passivation anti-reflection layer away from the substrate, the second sub-contact layer and the first sub-contact layer are integrated as a single member;
• wherein the tunnel layer is located on a surface of the front surface field layer away from the substrate.