4results about How to "Reduce recombination current" patented technology

The invention relates to the technical field of TOPCon solar cells, in particular to a TOPCon photovoltaic cell structure and a preparation method thereof, and the method comprises the steps: preparing a local patterning mask on a tunneling oxide layer through nanometer imprinting; and etching by using a high-selectivity etching agent and depositing a passivation layer, forming a local passivation structure on the polycrystalline silicon substrate, removing a mask material, depositing a polycrystalline silicon emitter layer and preparing an electrode, and forming a TOPCon photovoltaic cell structure. According to the invention, the local patterning mask is prepared on the tunneling oxide layer by using the nano imprinting technology, the high-selectivity etching solution is combined to form the local patterning structure, and finally the passivation layer material is deposited in the etched area to form the local patterning passivation layer, so that the contact interface is optimized, the recombination current between the front electrode and the silicon substrate is reduced, and the performance of the device is improved. Therefore, the open-circuit voltage and the filling factor of the cell are improved, and the photoelectric conversion efficiency is improved.

The embodiments of the present application relate to the field of photovoltaic technology, and in particular to a sliced ​​cell and a method for forming the same, and a photovoltaic module. The sliced ​​cell comprises: the sliced ​​cell is formed by slicing a whole cell, and the sliced ​​cell has a cutting surface formed by the slicing process; wherein at least part of the cutting surface has a first texture structure, and the first texture structure includes at least a plurality of rectangular portions, and at least one of the rectangular portions partially overlaps with at least one adjacent rectangular portion. The embodiments of the present application are at least conducive to improving the performance of the sliced ​​cell and the photovoltaic module.

The invention discloses a bipolar junction transistor (BJT) device, which is characterized in that a second heavily doped region and a first shallow trench isolation structure are arranged at an interval, and an isolation layer is arranged in an interval space between the second heavily doped region and the first shallow trench isolation structure, so that the influence of resistance voltage drop of a base region is reduced, and the current collector edge effect of an emitter is effectively inhibited. Meanwhile, since the second heavily doped region is far away from the first shallow trench isolation structure, recombination current generated at the edge of the first shallow trench isolation structure can be effectively reduced, the current of the second well region (base region) is also reduced, and the current gain of the BJT device is also improved.

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.