CPC H01L 31/02167 (2013.01) [H01L 31/02363 (2013.01); H01L 31/03125 (2013.01); H01L 31/0508 (2013.01)] | 20 Claims |
1. A solar cell, comprising:
an N-type substrate;
a P-type emitter formed on a first surface of the N-type substrate; and
a tunnel layer and a doped conductive layer sequentially formed over a second surface of the N-type substrate in a direction away from the N-type substrate;
wherein the P-type emitter comprises a first portion and a second portion, the first portion has first pyramid structures formed on a top surface of the first portion and the second portion has second pyramid structures formed on a top surface of the second portion;
wherein a transition surface is respectively formed on at least one edge of each first pyramid structure, the at least one edge has irregular deformation, the transition surface is joined with two adjacent inclined surfaces of the each first pyramid structure, and the transition surface is concave or convex relative to a center of the each first pyramid structure;
wherein a substructure is formed on each of top surfaces of at least a part of the first pyramid structures, and a shape of the substructure is spherical or spherical-like;
wherein edges of each second pyramid structure are straight; and
wherein a sheet resistance of the first portion ranges from 10 ohm/sq to 500 ohm/sq, a doping concentration at the top surface of the first portion ranges from 1E17 atoms/cm3 to 8E19 atoms/cm3; a sheet resistance of the second portion ranges from 100 ohm/sq to 1000 ohm/sq, and a doping concentration at the top surface of the second portion ranges from 1E16 atoms/cm3 to 5E19 atoms/cm3.
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