Solar cell and solar cell module

A solar cell comprising:

• a P-type silicon substrate in which one main surface is a light-receiving surface and the other main surface is a backside;
• a back surface passivation layer provided on a whole of the backside of the P-type silicon substrate;
• a backside electrode comprising a plurality of back surface electrodes provided in the back surface passivation layer so as to be in contact with the P-type silicon substrate in a plurality of contact areas, the plurality of back surface electrodes being connected with each other in such a manner that the plurality of back surface electrodes are integrated and formed over a whole surface of the back surface passivation layer;
• an N-type layer formed on at least a part of the light-receiving surface of the P-type silicon substrate;
• a light-receiving surface passivation layer;
• and
• a light-receiving surface electrode that is in electrical contact with the N-type layer,
• wherein:
• the P-type silicon substrate is a silicon single crystal substrate doped with gallium and is produced from an ingot grown by a Czochralski method;
• the P-type silicon substrate has a resistivity of 0.2 to 2.5 Ω·cm;
• a total area of the plurality of contact areas is in a range of from about 5 to 20% on the basis of the whole area of the backside;
• the plurality of contact areas has a pitch Prm [mm] of 0.1 to 10 mm;
• the pitch Prm [mm] of the plurality of contact areas and the resistivity Rsub [Ω·cm] of the P-type silicon substrate satisfy the relation represented by the following formula (1)
• log(Rsub)≤−log(Prm)+1.0 (1),
• a value of the pitch Prm [mm] further has a value is such that, with the proviso that the pitch Prm [mm] is in the horizontal axis and the resistivity Rsub [Ω·cm] is in the vertical axis, a short-circuit current density is more than 38 mA/cm2 and less than about 40 mA/cm2, and shows a smaller variation than the resistivity of the P-type silicon, substrate and the solar cell shows a similar current throughout the range of 0.2 to 2.5 Ω·cm of the resistivity of the P-type silicon substrate, and
• a conversion efficiency of the solar cell is about 20%.

A solar cell comprising:

• a P-type silicon substrate in which one main surface is a light-receiving surface and the other main surface is a backside;
• a back surface passivation layer provided on a whole of the backside of P-type silicon substrate;
• a backside electrode comprising a plurality of back surface electrodes provided in the back surface passivation layer so as to be regularly provided in contact with the P-type silicon substrate in a plurality of contact areas;
• an N-type layer formed on at least a part of the light-receiving surface of the P-type silicon substrate;
• a light-receiving surface passivation layer;
• and
• a light-receiving surface electrode that is in electrical contact with the N-type layer, wherein:
• the P-type silicon substrate is a silicon single crystal substrate doped with gallium;
• the P-type silicon substrate has a resistivity in a range of 0.2 to 2.5 Ω·cm;
• the P-type silicon substrate is produced from an ingot grown by a Czochralski method;
• the plurality of contact areas are provided in a plurality of regular patterns provided with a regular pitch;
• a total area of the plurality of contact areas is in a range of from about 5 to 20% on the basis of the whole area of the backside;
• a value of the regular pitch is such that, with the proviso that the pitch is in the horizontal axis and the resistivity is in the vertical axis, a short-circuit current density is more than 38 mA/cm2 and less than about 40 mA/cm2, shows smaller variations as compared to the resistivity of the P-type silicon;
• substrate, and the solar cell shows a similar current throughout the range of 0.2 to 2.5 Ω·cm of the resistivity of the P-type silicon substrate;
• and
• a conversion efficiency of the solar cell is about 20%.

A solar cell comprising:

• a P-type silicon single crystal substrate doped with gallium and having a resistivity of 0.2 to 2.5 Ω·cm in which one main surface is a light-receiving surface and the other main surface is a backside, the P-type silicon single crystal substrate being produced from an ingot grown by a Czochralski method;
• an N-type layer formed on at least a part of the light-receiving surface of the P-type silicon single crystal substrate;
• and
• a backside electrode comprising a plurality of back surface electrodes formed onto the backside of the P-type silicon single crystal substrate, wherein a back surface electrode pitch Prm [mm] of the plurality of the back surface electrodes and the resistivity Rsub [Ω·cm] of the P-type silicon substrate satisfy the relation represented by the following formula (1)
• log(Rsub)≤−log(Prm)+1.0 (1),
• wherein:
• the back surface electrode pitch Prm [mm] has a value such that, with the proviso that the pitch Prm [mm] is in the horizontal axis of a diagram shown by Rsub versus Prm and the resistivity Rsub [Ω·cm] of the P-type silicon single crystal substrate is in the vertical axis of the diagram, a variation in a short-circuit current density of the solar cell is smaller as compared to a variation in the resistivity of the P-type silicon single crystal substrate, the short-circuit current density is within a value defined by the lines of 0.2 Ω·cm and 2.5 Ω·cm of the resistivity of the substrate and the line of log (Rsub)=−log (Prm)+1.0, and the solar cell has a similar current throughout the range of 0.2 to 2.5 Ω·cm of the resistivity of the P-type silicon single crystal substrate,
• the back surface electrode pitch is 0.1 mm or more and 10 mm or less,
• a total area of contact areas of the back surface electrodes is in a range of from about 5 to 20%, on the basis of the whole area of the backside, and
• a conversion efficiency of the solar cell is about 20%.

A solar cell comprising:

• a P-type silicon single crystal substrate doped with gallium and having a resistivity of 0.2 to 2.5 Ω·cm in which one main surface of the substrate is a light-receiving surface and the other main surface is a backside, the P-type silicon single crystal substrate being produced from an ingot grown by a Czochralski method;
• an N-type layer formed on at least a part of the light-receiving surface of the P-type silicon single crystal substrate;
• and
• a backside electrode comprising a plurality of back surface electrodes formed on the backside of the P-type silicon single crystal substrate with a back surface electrode pitch Prm [mm];
• wherein the back surface electrode pitch and the resistivity Rsub [Ω·cm] of the P-type silicon single crystal substrate satisfy the relation represented by the following formula (1)
• log(Rsub)≤−log(Prm)+1.0 (1);
• and
• the back surface electrodes are in electrical contact with the backside of the substrate;
• and wherein:
• the back surface electrode pitch Prm [mm] has a value such that, with the proviso that the pitch Prm [mm] is in the horizontal axis of a diagram shown by Rsub versus Prm and the resistivity Rsub [Ω·cm] of the P-type silicon single crystal substrate is in the vertical axis of the diagram, a variation in a short-circuit current density of the solar cell is smaller as compared to a variation in the resistivity of the P-type silicon single crystal substrate, the short-circuit current density is within a value defined by the lines of 0.2 Ω·cm and 2.5 Ω·cm of the resistivity of the substrate and the line of log (Rsub)=−log (Prm)+1.0, and the solar cell has a similar current throughout the range of 0.2 to 2.5 Ω·cm of the resistivity of the P-type silicon single crystal substrate,
• the back surface electrode pitch is 0.1 mm or more and 10 mm or less,
• a total area of contact areas of the back surface electrodes is in a range of from about 5 to 20%, on the basis of the whole area of the backside, and
• a conversion efficiency of the solar cell is about 20%.

A solar cell comprising:

• (i) a P-type silicon single crystal substrate doped with gallium and having a resistivity of 0.2 to 2.5 Ω·cm in which one main surface is a light-receiving surface and the other main surface is a backside, the P-type silicon single crystal substrate being produced from an ingot grown by a Czochralski method;
• (ii) a backside electrode comprising a plurality of back surface electrodes in electrical contact with the P-type silicon single crystal substrate in a plurality of contact areas;
• wherein the contact areas have a pitch Prm [mm] of 0.1 to 10 mm, and the pitch Prm [mm] further has a value such that, with the proviso that the pitch is in a horizontal axis of a diagram shown by Rsub versus Prm and the resistivity of the P-type silicon single crystal substrate is in a vertical axis of the diagram, a variation in a short-circuit current density of the solar cell is smaller as compared to a variation in the resistivity of the P-type silicon single crystal substrate, the short-circuit current density is within a value defined by the lines of 0.2 Ω·cm and 2.5 Ω·cm and the line of log (Rsub)=−log (Prm)+1.0, and the solar cell shows a similar current throughout the range of 0.2 to 2.5 Ω·cm of the resistivity of the P-type silicon single crystal substrate;
• (iii) an N-type layer formed on at least a part of the light-receiving surface;
• (iv) a back surface passivation layer formed on the whole of the backside;
• (v) a light-receiving surface passivation layer;
• and
• (vi) a light-receiving surface electrode in electrical contact with the N-type layer,
• wherein the pitch Prm [mm] of the contact areas and the resistivity Rsub [Ω·cm] satisfy the relationship represented by the following formula (1)
• log(Rsub)≤−log(Prm)+1.0 (1),
• wherein a total area of the contact areas of the back surface electrodes is in a range of from about 5 to 20%, on the basis of the whole area of the backside, and
• wherein a conversion efficiency of the solar cell is about 20%.

A solar cell comprising:

• a P-type silicon substrate in which one main surface is a light-receiving surface and the other main surface is a backside, wherein:
• the P-type silicon substrate is a silicon single crystal substrate doped with gallium and is produced from an ingot grown by a Czochralski method, and
• the P-type silicon substrate has a resistivity in a range of 0.2 to 2.5 Ω·cm;
• an N-type layer on at least a part of the light-receiving surface of the P-type silicon substrate;
• a surface passivation layer on the backside of the P-type silicon substrate;
• a first electrode on the light-receiving surface;
• and
• a second electrode comprising a plurality of back surface electrodes on the backside of the P-type silicon substrate;
• wherein:
• the plurality of back surface electrodes penetrate through the surface passivation layer to contact the P-type silicon substrate in a plurality of contact areas which are provided in a plurality of regular patterns provided with a regular pitch;
• a value of the regular pitch is such that a short-circuit current density of the solar cell shows a smaller variation as compared to the resistivity of the P-type silicon substrate, and the solar cell has a similar current throughout the range of the resistivity of 0.2 to 2.5 Ω·cm of the P-type silicon substrate;
• the total area of the plurality of contact areas of the back surface electrodes is about 5% or more and 20% or less on the basis of the whole of the backside;
• and
• a conversion efficiency of the solar cell is about 20%.