Heterojunction solar cell and method for producing a heterojunction solar cell

A method for producing a heterojunction solar cell comprising:

• providing an n-type silicon substrate having a front surface and a back surface opposite to each other;
• forming a first passivation layer and a second passivation layer sequentially on the front surface of the n-type silicon substrate;
• forming a third passivation layer, wherein the third passivation layer is located on and in contact with the back surface, the third passivation layer includes hydrogenated amorphous silicon;
• forming a fourth passivation layer, wherein the fourth passivation layer is located on and in contact with a surface of the third passivation layer away from the n-type silicon substrate, the fourth passivation layer includes hydrogenated nanocrystalline silicon;
• forming a fifth passivation layer located on a surface of the second passivation layer away from the n-type silicon substrate, wherein a material of the fifth passivation layer is hydrogenated n-type microcrystalline silicon or nanocrystalline silicon oxycarbide;
• and
• forming a silicon oxycarbide layer on a surface of the fourth passivation layer away from the n-type silicon substrate, wherein the silicon oxycarbide layer is in contact with the surface of the fourth passivation layer away from the n-type silicon substrate, the silicon oxycarbide layer is p-type doped to form a PN junction with n-type silicon substrate, a dopant of the silicon oxycarbide layer includes boron, wherein the atomic percentage of carbon in the silicon oxycarbide layer is equal to or greater than 7 times the atomic percentage of oxygen in the silicon oxycarbide layer.