Solar cell and photovoltaic module

A solar cell, comprising:

• a substrate having a first surface and a second surface arranged opposite to each other along a thickness direction of the substrate;
• an emitter structure, arranged on the first surface of the substrate, and comprising a first heavily doped region and a first lightly doped region arranged alternately;
• a doped conductive structure, disposed on the second surface of the substrate, and comprising a second heavily doped region and a second lightly doped region alternately arranged;
• the second heavily doped region, the second lightly doped region and the substrate having the same conductivity type;
• a first electrode disposed at least on the first heavily doped region of the emitter structure and electrically connected to the first heavily doped region;
• and
• a second electrode disposed at least on the second heavily doped region of the doped conductive structure and electrically connected to the second heavily doped region;
• wherein a doping concentration index of the first heavily doped region is greater than a doping concentration index of the first lightly doped region;
• the doping concentration index of the first heavily doped region is a ratio of an average doping concentration of the first heavily doped region within a preset depth range to a doping concentration of the substrate, and the doping concentration index of the first lightly doped region is a ratio of an average doping concentration of the first lightly doped region within the preset depth range to the doping concentration of the substrate;
• and
• a doping concentration index of the second heavily doped region is greater than a doping concentration index of the second lightly doped region;
• the doping concentration index of the second heavily doped region is a ratio of an average doping concentration of the second heavily doped region within the preset depth range to the doping concentration of the substrate, and the doping concentration index of the second lightly doped region is a ratio of an average doping concentration of the second lightly doped region within the preset depth range to the doping concentration of the substrate;
• wherein the doping concentration index of the first heavily doped region is in a range from 10 to 1×107, and the doping concentration index of the first lightly doped region is in a range from 1 to 100;
• the doping concentration index of the second heavily doped region is in a range from 10 to 1×107, and the doping concentration index of the second lightly doped region is in a range from 1 to 100;
• and
• the preset depth range is from 90 nm to 110 nm.