SOLAR CELL, SOLAR CELL MODULE, AND METHOD FOR MANUFACTURING SOLAR CELL
A solar cell including a single crystal silicon substrate having electrical characteristic distribution, which is line-symmetric with respect to the center line in plan view, and in which portions equidistant from the center line have an electrical characteristic substantially uniform in an extending direction of the center line in the plan view, a semiconductor junction formed by using the single-crystal silicon substrate, and an electrode.
1 . A solar cell comprising:
a single-crystal silicon substrate having electrical characteristic distribution that is line symmetric with respect to a center line in a plan view and in which portions equidistant from the center line have an electrical characteristic substantially uniform in an extending direction of the center line in the plan view;
a semiconductor junction formed by using the single-crystal silicon substrate; and
an electrode.
2 . The solar cell according to claim 1 , wherein the electrode includes: a bus bar electrode portion extending, in the plan view, in the extending direction of the center line along which the electrical characteristic is substantially uniform; and a finger electrode portion extending in a direction intersecting the extending direction of the center line in the plan view.
3 . The solar cell according to claim 2 , wherein
a plurality of the finger electrode portions are provided, and
output characteristics of regions respectively from which the finger electrode portions collect electricity are substantially equivalent to each other.
4 . The solar cell according to claim 1 , wherein a main surface of the single-crystal silicon substrate is a (100) plane.
5 . The solar cell according to claim 1 , wherein the electrical characteristic is substantially uniform from one end to another end of the single-crystal silicon substrate in the extending direction of the center line.
6 . The solar cell according to claim 1 , wherein the electrical characteristic includes lifetime and resistivity.
7 . The solar cell according to claim 1 , wherein
the single-crystal silicon substrate includes a high-level electrical characteristic region in which the electrical characteristics are relatively good and low-level electrical characteristic regions in which the electrical characteristics are relatively poor,
the high-level electrical characteristic region and the low-level electrical characteristic regions are both configured to be substantially line symmetric with respect to the center line, and
the low-level electrical characteristic regions are arranged outside the high-level electrical characteristic region when viewed from the center line.
8 . The solar cell according to claim 1 , wherein
the single-crystal silicon substrate includes a single-crystal silicon substrate of a first conductivity type, and
the semiconductor junction includes:
the single-crystal silicon substrate of the first conductivity type;
a substantially-intrinsic first amorphous semiconductor layer which is formed on the single-crystal silicon substrate of the first conductivity type; and
a second amorphous semiconductor layer of a second conductivity type which is formed on the first amorphous semiconductor layer.
9 . A solar cell module comprising solar cells electrically connected to one another in series, the solar cells each including:
a single-crystal silicon substrate having electrical characteristic distribution which is line symmetric with respect to a center line in a plan view and in which portions equidistant from the center line have an electrical characteristic substantially uniform in an extending direction of the center line in the plan view;
a semiconductor junction formed by using the single-crystal silicon substrate; and
an electrode.
10 . The solar cell module according to claim 9 , wherein the electrical characteristics of the single-crystal silicon substrates of neighboring solar cells among the solar cells are substantially equivalent to each other.
11 . The solar cell module according to claim 9 , wherein the electrode of each of the solar cells includes: a bus bar electrode portion extending, in the plan view, in the extending direction of the center line along which the electrical characteristic is substantially uniform; and a finger electrode portion extending in a direction intersecting the extending direction of the center line in the plan view.
12 . The solar cell module according to claim 11 , wherein
a plurality of the finger electrode portions are provided in each of the solar cells, and
output characteristics of regions respectively from which the finger electrode portions collect electricity are substantially equivalent to each other.
13 . The solar cell module according to claim 9 , wherein a main surface of the single-crystal silicon substrate of each of the solar cells is a (100) plane.
14 . The solar cell module according to claim 9 , wherein the electrical characteristics of the single-crystal silicon substrate of each of the solar cells are substantially uniform from one end to another end of the single-crystal silicon substrate in the extending direction of the center line.
15 . The solar cell module according to claim 9 , wherein the electrical characteristic of the single-crystal silicon substrate of each of the solar cells includes lifetime and resistivity.
16 . The solar cell module according to claim 9 , wherein
the single-crystal silicon substrate of each of the solar cells includes a high-level electrical characteristic region in which the electrical characteristics are relatively good and low-level electrical characteristic regions in which the electrical characteristics are relatively poor,
the high-level electrical characteristic region and the low-level electrical characteristic regions are both configured to be substantially line symmetric with respect to the center line, and
the low-level electrical characteristic regions are arranged outside the high-level electrical characteristic region when viewed from the center line.
17 . The solar cell module according to claim 9 , wherein
the single-crystal silicon substrate of each of the solar cells includes a single-crystal silicon substrate of a first conductivity type, and
the semiconductor junction of each of the solar cells includes:
the single-crystal silicon substrate of the first conductivity type;
a substantially-intrinsic first amorphous semiconductor layer which is formed on the single-crystal silicon substrate of the first conductivity type; and
a second amorphous semiconductor layer of a second conductivity type which is formed on the first amorphous semiconductor layer.
18 . A method for manufacturing a solar cell comprising the steps of:
forming a single-crystal silicon ingot having concentric electrical characteristic distribution by crystal growth;
slicing the single-crystal silicon ingot along a plane parallel to a growth direction of the single-crystal silicon ingot and thereby forming a single-crystal silicon substrate having electrical characteristic distribution which is line symmetric with respect to a center line and in which portions equidistant from the center line have an electrical characteristic substantially uniform in an extending direction of the center line;
forming a semiconductor junction by using the single-crystal silicon substrate; and
forming an electrode.
19 . The method for manufacturing a solar cell according to claim 18 , wherein the step of forming the electrode includes a step of forming: a bus bar electrode portion extending, in a plan view, in the extending direction of the center line along which the electrical characteristic is substantially uniform; and a finger electrode portion extending in a direction intersecting the extending direction of the center line in the plan view.
20 . The method for manufacturing a solar cell according to claim 18 , wherein the step of forming the single-crystal silicon substrate includes a step of forming the single-crystal silicon substrate in such a way that a main surface of the single-crystal silicon substrate is a (100) plane.