Solar cell and photovoltaic module

A solar cell, comprising:

• a semiconductor substrate comprising a first surface and a second surface that are opposite to each other;
• a first dielectric layer located on the first surface;
• a first N+ doped layer located on a surface of the first dielectric layer;
• a first passivation layer located on a surface of the first N+ doped layer;
• a first electrode located on a surface of the first passivation layer;
• a second dielectric layer located on the second surface;
• a first P+ doped layer located on a surface of the second dielectric layer;
• a second passivation layer located on a surface of the first P+ doped layer;
• and
• a second electrode located on a surface of the second passivation layer,
• wherein the semiconductor substrate is a P-type semiconductor substrate, the first surface is a back surface of the semiconductor substrate, and the second surface is a front surface of the semiconductor substrate,
• wherein at least one region on the surface of the first P+ doped layer is further provided with a fourth dielectric layer and a second P+ doped layer, and the second electrode penetrates through the second passivation layer to be in contact with the second P+ doped layer,
• wherein the at least one region on the surface of the first P+ doped layer corresponds to a region of the second electrode,
• wherein the first N+ doped layer has a doping concentration in a range from 2×1020 cm−3 to 6×1020 cm−3,
• wherein a thickness of the second P+ doped layer is greater than a thickness of the first P+ doped layer, and
• wherein the first dielectric layer has a different thickness from the second dielectric layer.

A photovoltaic module, comprising solar cells, wherein at least part of the solar cells is connected to each other in a splicing or stacking manner and sealed by an encapsulating material, wherein one of the solar cells comprises:

• a semiconductor substrate comprising a first surface and a second surface that are opposite to each other;
• a first dielectric layer located on the first surface;
• a first N+ doped layer located on a surface of the first dielectric layer;
• a first passivation layer located on a surface of the first N+ doped layer;
• a first electrode located on a surface of the first passivation layer;
• a second dielectric layer located on the second surface;
• a first P+ doped layer located on a surface of the second dielectric layer;
• a second passivation layer located on a surface of the first P+ doped layer;
• and
• a second electrode located on a surface of the second passivation layer,
• wherein the semiconductor substrate is an N-type semiconductor substrate, the first surface is a front surface of the semiconductor substrate, and the second surface is a back surface of the semiconductor substrate,
• wherein at least one region on the surface of the first N+ doped layer is further provided with a third dielectric layer and a second N+ doped layer, and the first electrode penetrates through the first passivation layer to be in contact with the second N+ doped layer,
• wherein the at least one region on the surface of the first N+ doped layer corresponds to a region of the first electrode,
• wherein the first N+ doped layer has a doping concentration in a range from 2×1020 cm−3 to 6×1020 cm−3,
• wherein a thickness of the second N+ doped layer is greater than a thickness of the first N+ doped layer, and
• wherein the first dielectric layer has a different thickness from the second dielectric layer.