1results about How to "Reduce recombination current" patented technology

This invention discloses a TOPCon battery and its fabrication method, belonging to the field of TOPCon battery technology. It includes a monocrystalline silicon wafer with a tunneling layer, a doped polycrystalline silicon layer, a back anti-reflection layer, and a back metal electrode sequentially disposed on its back side from the inside out. The doped polycrystalline silicon layer includes a first doped polycrystalline silicon region and a second doped polycrystalline silicon region. The first doped polycrystalline silicon region is in contact with the back metal electrode and is disposed on the surface of a groove. The tunneling oxide layer is relatively thin, and the inward junction depth is greater than that of the second doped polycrystalline silicon region. This effectively prevents electrode metal from penetrating into the junction region, reduces metal recombination current, and improves the battery's open-circuit voltage. Furthermore, the first doped polycrystalline silicon region has a larger contact area with the printing paste, reducing the battery's contact resistance. Simultaneously, the groove prevents the printing paste from widening outward, ensuring a high grid line aspect ratio, reducing grid line resistance, and thus improving the battery's fill factor.