Solar cell and photovoltaic module

A photovoltaic module, comprising:

• a plurality of cell strings, each formed by connecting a plurality of solar cells;
• an encapsulation film, configured to cover surfaces of the plurality of cell strings;
• and
• a cover plate, configured to cover a surface of the encapsulation film facing away from the plurality of cell strings;
• wherein each of the plurality of solar cells comprises:
• a silicon substrate, having a front surface and a rear surface opposite to the front surface, wherein the silicon substrate includes at least one of a phosphorus (P) element, a bismuth (Bi) element, an antimony (Sb) element, or an arsenic (As) element;
• a passivation layer including an aluminum oxide (AlxOy) material formed over the front surface, wherein ⅓≤x/y≤3, x/y representing a ratio of content of aluminum to content of oxygen in the passivation layer;
• a first antireflection layer including a silicon nitride “(SiiNj)” material formed over the passivation layer, wherein 0.5≤i/j≤10, i/j representing a ratio of content of silicon to content of nitrogen in the first antireflection layer;
• a second antireflection layer including a silicon oxynitride (SicNdOe) material formed over the first antireflection layer, wherein 0.5≤c/d≤10, and 0.25≤d/e≤2, c/d representing a ratio of content of silicon to content of nitrogen in the second antireflection layer, and d/e representing a ratio of content of nitrogen to content of oxygen in the second antireflection layer;
• a third antireflection layer including a silicon oxide (SiaOb) material formed over the second antireflection layer, wherein 0.5≤a/b≤3, a/b representing a ratio of content of silicon to content of oxygen in the third antireflection layer;
• a tunneling dielectric layer formed over the rear surface;
• and
• a doped conductive layer formed over the tunneling dielectric layer;
• wherein in a direction away from the first antireflection layer, content percentage of silicon in the second antireflection layer gradually decreases, content percentage of nitrogen in the second antireflection layer gradually decreases, and content percentage of oxygen in the second antireflection layer gradually increases;
• wherein the second antireflection layer includes a plurality second sub-antireflection layers stacked in the direction away from the first antireflection layer, each of the plurality of second sub-antireflection layers includes a silicon oxynitride material;
• and
• wherein in the direction away from the first antireflection layer, content percentage of silicon in the plurality of second sub-antireflection layers decreases layer by layer, content percentage of nitrogen in the plurality of second sub-antireflection layers decreases layer by layer, and content percentage of oxygen in the plurality of second sub-antireflection layers increases layer by layer.