The present disclosure relates to the field of solar cell technologies. The present disclosure provides a solar cell and a manufacturing method therefor, a photovoltaic module, and a photovoltaic system. The solar cell includes: a substrate; a tunnel oxide layer stacked on a surface of the substrate, the tunnel oxide layer being an oxide layer including at least a silicon element and an oxygen element; and a polysilicon doped conductive layer stacked on a side of the tunnel oxide layer facing away from the substrate. The tunnel oxide layer is doped with a carbon element and a hydrogen element.

This present disclosure provides a back contact solar cell and a photovoltaic module. In one example, a back contact solar cell includes a silicon substrate, a P-type doped polysilicon layer, and an N-type doped polysilicon layer, where the silicon substrate includes a first side and a second side opposite to the first side. The P-type doped polysilicon layer is located in a first region on the first side of the silicon substrate, and the N-type doped polysilicon layer is located in a second region on the first side of the silicon substrate, where the first region is different from the second region. A ratio of a thickness of the P-type doped polysilicon layer to a thickness of the N-type doped polysilicon layer ranges from 1 to 2.

In a solar cell, the back surface of a substrate thereof is provided with alternately distributed emitter zones and back surface field zones. An emitter is formed in each emitter zone, and the emitters are made of boron-doped monocrystalline silicon. A back surface field is formed in each back surface field zone; the back surface fields comprise tunneling oxide layers and polycrystalline silicon layers in stacked distribution, the polycrystalline silicon layers being made of phosphorus-doped polycrystalline silicon, and the tunneling oxide layers being located between a polycrystalline silicon layer and a polycrystalline silicon layer. Positive electrodes are electrically connected to the emitters, and negative electrodes are electrically connected to the back surface fields. In the described solar cell, the light-receiving area of the front surface can be expanded and the recombination rate of electron-hole pairs can be reduced, thereby effectively improving the photoelectric conversion efficiency of the solar cell.

Embodiments of the present disclosure relate to a solar cell, a method for preparing the solar cell, and a solar cell production line. The method includes providing a stack including an N-type silicon substrate having a boron-doped polysilicon layer near a first surface, with a tunneling oxide layer, a phosphorus-doped polysilicon layer, and a mask layer sequentially stacked as stated on an opposite second surface; forming through holes in the mask layer to expose the phosphorus-doped polysilicon layer; forming grooves at the through holes that extend through the phosphorus-doped polysilicon layer and the tunneling oxide layer and partially extend into the N-type silicon substrate, thereby separating a surface of the stack provided with the phosphorus-doped polysilicon layer into spaced emitter regions, and removing the mask layer.