Semiconductor substrate, solar cell, and photovoltaic module

A solar cell, comprising:

• a semiconductor substrate, including:
• a back surface including N-type conductive regions and P-type conductive regions formed thereon,
• wherein the N-type conductive regions are provided with first non-pyramidal texture structures, and the P-type conductive regions are provided with second non-pyramidal texture structures;
• and each of the first non-pyramidal texture structures and the second non-pyramidal texture structures is formed as a shape resulting from destruction of a spire of a pyramidal microstructure that protrudes towards a direction away from the back surface of the semiconductor substrate;
• a top surface of the first non-pyramidal texture structure is a polygonal plane and a top surface of the second non-pyramidal texture structure is a polygonal plane, and a one-dimensional size of the top surface of the first non-pyramidal texture structure in a dimension is less than a one-dimensional size of the top surface of the second non-pyramidal texture structure in the same dimension, the one-dimensional size being a length, a width, a diagonal length, or a circular diameter of the top surface;
• and
• the one-dimensional size of the top surface of the first non-pyramidal texture structure is greater than or equal to 5 μm and less than or equal to 12 μm;
• and the one-dimensional size of the top surface of the second non-pyramidal texture structure is greater than or equal to 10 μm and less than or equal to 40 μm;
• a tunnel oxide layer formed over the N-type conductive region;
• a local back surface field formed in the P-type conductive region;
• a polysilicon film layer formed over a side of the tunnel oxide layer facing away from the semiconductor substrate;
• an eutectic layer formed in the local back surface field;
• a back-surface passivation layer formed over a side of the polysilicon film layer facing away from the tunnel oxide layer and over the P-type conductive region;
• a first electrode passing through the back-surface passivation layer to form ohmic contact with the local back surface field;
• and
• a second electrode passing through the back-surface passivation layer to form ohmic contact with the polysilicon film layer.

A photovoltaic module, comprising:

• a plurality of solar cells electrically connected into a solar cell string in a form of an entire cell or multiple-cut cells,
• wherein at least one of the plurality of solar cells includes:
• a semiconductor substrate, including:
• a back surface including N-type conductive regions and P-type conductive regions formed thereon,
• wherein the N-type conductive regions are provided with first non-pyramidal texture structures, and the P-type conductive regions are provided with second non-pyramidal texture structures;
• and each of the first non-pyramidal texture structures and the second non-pyramidal texture structures is formed as a shape resulting from destruction of a spire of a pyramidal microstructure that protrudes towards a direction away from the back surface of the semiconductor substrate;
• a top surface of the first non-pyramidal texture structure is a polygonal plane and a top surface of the second non-pyramidal texture structure is a polygonal plane, and a one-dimensional size of the top surface of the first non-pyramidal texture structure in a dimension is less than a one-dimensional size of the top surface of the second non-pyramidal texture structure in the same dimension, the one-dimensional size being a length, a width, a diagonal length, or a circular diameter of the top surface;
• and
• the one-dimensional size of the top surface of the first non-pyramidal texture structure is greater than or equal to 5 μm and less than or equal to 12 μm;
• and the one-dimensional size of the top surface of the second non-pyramidal texture structure is greater than or equal to 10 μm and less than or equal to 40 μm;
• a tunnel oxide layer formed over the N-type conductive region;
• a local back surface field formed in the P-type conductive region;
• a polysilicon film layer formed over a side of the tunnel oxide layer facing away from the semiconductor substrate;
• an eutectic layer formed in the local back surface field;
• a back-surface passivation layer formed over a side of the polysilicon film layer facing away from the tunnel oxide layer and over the P-type conductive region;
• a first electrode passing through the back-surface passivation layer to form ohmic contact with the local back surface field;
• and
• a second electrode passing through the back-surface passivation layer to form ohmic contact with the polysilicon film layer.