Solar cell and solar cell module

A solar cell module, comprising:

• at least one cell string formed by connecting a plurality of solar cells;
• at least one encapsulation film configured to cover a surface of the at least one cell string;
• and
• at least one cover plate configured to cover a surface of the at least one encapsulation film facing away from the at least one cell string;
• wherein each solar cell of the plurality of solar cells includes:
• a substrate having a first surface and an opposing second surface, wherein the solar cell has a first region and a second region;
• a tunneling layer including a first dielectric layer disposed on a portion of the second surface of the substrate corresponding to the first region and a second dielectric layer;
• a first emitter disposed on a surface of the first dielectric layer away from the substrate;
• wherein the second dielectric layer is formed on another portion of the second surface corresponding to the second region and on a third surface and a sidewall of the first emitter, and the third surface is a surface of the first emitter facing away from the first dielectric layer;
• a second emitter disposed on the second dielectric layer, a conductivity type of the second emitter being different from a conductivity type of the first emitter;
• a first electrode disposed in the first region and electrically connected with the first emitter by penetrating through the second emitter and further penetrating through the second dielectric layer;
• and
• a second electrode disposed in the second region and electrically connected with the second emitter;
• wherein a dielectric constant of a material of the second dielectric layer is smaller than a dielectric constant of a material of the first dielectric layer, and a thickness of the second dielectric layer is smaller than a thickness of the first dielectric layer;
• and
• wherein the second emitter includes a first doped portion and a second doped portion, at least part of the second doped portion directly contacts the first electrode and is disposed between the first doped portion and the first electrode, doping concentration anywhere in the first doped portion is greater than or equal to doping concentration anywhere in the second doped portion, and doping concentration in the second doped portion decreases in a direction from the first doped portion towards the first electrode.