| CPC H01L 31/02167 (2013.01) [H01L 31/02363 (2013.01); H01L 31/035281 (2013.01)] | 20 Claims |

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1. A cell assembly, comprising:
a silicon substrate;
a first doped region and a second doped region, alternately disposed on a back side of the silicon substrate and having opposite polarities;
a first dielectric layer, disposed on a front side of the silicon substrate;
a second dielectric layer, wherein an orthogonal projection of at least a portion of the second dielectric layer onto the silicon substrate is disposed between orthogonal projections of the first doped region and the second doped region along a lateral direction of the silicon substrate; and
a first conductive layer and a second conductive layer, respectively disposed in the first doped region and the second doped region;
wherein:
each of the first and second doped regions comprises a first doped layer, a passivation layer, and a second doped layer;
the first doped layer of the first doped region is a part of the silicon substrate;
the passivation layer of the first doped region is provided on the first doped layer of the first doped region; and
the passivation layer of the first doped region and the passivation layer of the second doped region are of a porous structure, wherein the porous structure comprises a hole region, and at least one of a part of the first doped layer or a part of the second doped layer is disposed in the hole region;
one of the first doped region and the second doped region is a P-type doped region, and the other of the first doped region and the second doped region is an N-type doped region;
a hole density of the passivation layer in the P-type doped region is greater than a hole density of the passivation layer in the N-type doped region.
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