This application provides a heterojunction solar cell and a preparation method. The heterojunction solar cell includes: a silicon substrate being n-type or p-type doped, and having a front surface and a back surface opposite to each other; a first passivation layer and a second passivation layer sequentially located on the front surface of the silicon substrate; a third passivation layer and a fourth passivation layer sequentially located on the back surface of the silicon substrate; a silicon oxycarbide layer located on a surface of the fourth passivation layer away from the silicon substrate, wherein the silicon oxycarbide layer is n-type or p-type doped to form PN junction with the silicon substrate, an atomic percentage of carbon is greater than an atomic percentage of oxygen in the silicon oxycarbide layer. The heterojunction solar cell of the present application improves the performance of the solar cell. The carbon and the oxygen in the silicon oxycarbide layer have a fixed effect on the hydrogen, which is beneficial for reducing the loss of hydrogen.

A solar cell includes a substrate, a transparent conductive film layer and a composite metal grid structure. The transparent conductive film layer is disposed on a side or both sides of the substrate; and the composite metal grid structure is disposed on a side, away from the substrate, of the transparent conductive film layer, and the transparent conductive film layer is electrically connected to the composite metal grid structure. The composite metal grid structure includes a first electrode layer and a second electrode layer, and the first electrode layer is located between the transparent conductive film layer and the second electrode layer. The composite metal grid structure including the first electrode layer and the second electrode layer is used in the solar cell, so that stability is relatively high, consumption of silver may be reduced to lower costs, electrical performance is good, and conversion efficiency can be improved.

A solar cell includes a substrate, a transparent conductive film layer and a composite metal grid structure. The transparent conductive film layer is disposed on a side or both sides of the substrate; and the composite metal grid structure is disposed on a side, away from the substrate, of the transparent conductive film layer, and the transparent conductive film layer is electrically connected to the composite metal grid structure. The composite metal grid structure includes a first electrode layer and a second electrode layer, and the first electrode layer is located between the transparent conductive film layer and the second electrode layer. The composite metal grid structure including the first electrode layer and the second electrode layer is used in the solar cell, so that stability is relatively high, consumption of silver may be reduced to lower costs, electrical performance is good, and conversion efficiency can be improved.

A heterojunction solar cell and a preparation method therefor. The heterojunction solar cell comprises: a semiconductor substrate layer; and a back composite transparent conductive film located on one side of the semiconductor substrate layer. The back surface composite transparent conductive film comprises: a first back surface transparent conductive film; and a second back transparent conductive film located on the side surface of the first back transparent conductive film facing away from the semiconductor substrate layer. Both the first back transparent conductive film and the second back transparent conductive film are doped with group III heavy atoms, and the concentration of the group III heavy atoms in the second back transparent conductive film is less than that of the group III heavy atoms in the first back transparent conductive film.

A heterojunction solar cell and a preparation method therefor. The heterojunction solar cell comprises: a semiconductor substrate layer; and a back composite transparent conductive film located on one side of the semiconductor substrate layer. The back surface composite transparent conductive film comprises: a first back surface transparent conductive film; and a second back transparent conductive film located on the side surface of the first back transparent conductive film facing away from the semiconductor substrate layer. Both the first back transparent conductive film and the second back transparent conductive film are doped with group III heavy atoms, and the concentration of the group III heavy atoms in the second back transparent conductive film is less than that of the group III heavy atoms in the first back transparent conductive film.