Solar cell and photovoltaic module

A solar cell, comprising:

• a substrate having an N-type conductivity;
• a patterned first passivating contact structure disposed on a light-receiving surface of the substrate, the first passivating contact structure comprising a first dielectric layer disposed adjacent to the substrate, and a first doped polysilicon layer disposed away from the substrate and having the N-type conductivity, wherein a thickness of the first dielectric layer is less than or equal to 2 nm;
• a second passivating contact structure disposed on an entirety of a back surface of the substrate, the second passivating contact structure comprising a second dielectric layer disposed adjacent to the substrate and a second doped polysilicon layer disposed away from the substrate, the second doped polysilicon layer having a P-type conductivity different from the N-type conductivity to form a PN junction between the second doped polysilicon layer and the substrate, wherein a thickness of the second dielectric layer is greater than 2 nm, the second dielectric layer has a through-hole that communicates the substrate with the second doped polysilicon layer, and a doping concentration of a P-type conductive element in the second doped polysilicon layer is in a range from 5×1018 atoms/cm3 to 3×1020 atoms/cm3;
• a first function layer disposed on the light-receiving surface of the substrate and a surface of the first doped polysilicon layer away from the substrate;
• a second function layer disposed on a surface of the second doped polysilicon layer away from the substrate;
• a first electrode extending through the first function layer and forming an ohmic contact with the first doped polysilicon layer, wherein a patterned region of the first passivating contact structure is disposed corresponding to a patterned region of the first electrode;
• and
• a second electrode extending through the second function layer and forming an ohmic contact with the second doped polysilicon layer.